A very mild Christmas

At this time last year we were just emerging from our biggest December freeze for 120 years. Snow lay on the ground. albeit in the form of large icy patches, and after a maximum temperature of just minus 0.9 Celsius on Christmas Day, Boxing Day dawned with a low of minus 6.8 Celsius. This December, mild, but unremarkably so, has not seen temperatures anywhere the values recorded last year. Yesterday (Christmas Day) was the mildest in this area for 13 years, and today, with the temperature nudging 13 Celsius, is also the mildest Boxing Day since 1998. Last year, the temperature failed to rise above 10 Celsius during the whole of December, but for snow lovers the rest of the winter was a dismall failure. A few flakes of snow were observed in the rain on 3 days during January and no snow fell in February. So what of the rest of the winter of 1998/1999? Apart from a brief snowy spell at the beginning of the second week of February, southwesterly winds prevailed bringing plenty of mild changeable weather; and this winter?........

No snow......yet!

The Christmas trees are all lined up ready for the festivities, but this year it's looking as if the Christmas period will be green, as it usually is of course! On this day last year the temperature reached 8 Celsius, but it was also the first day of the month with no snow observed in the garden. The snow returned on the 16th, and although it was not a 'true' white Christmas with snow falling, there was enough of the white stuff around to produce a supply of icy snowballs. A white Christmas with snow falling is much rarer than a December without snow falling. There has been some snow falling in the last 3 Decembers, but prior to that 4 out of 6 Decembers were completely free of snow. Also, the definition of 'snow' to the meteorologist is any preciptation that contains snow flakes whether partially melted on not. So, a cold and wet day with the odd blob of very wet snow is registered as a 'day with snow' . It remains to be seen if this December gets it's day of snow, but in the last 40 years there have been 16 snow-free Decembers in this area. The odds of seeing snow this month are good.....but not very good!

Second Best

The frost has left the banana looking sad but all the talk is about the warmth of November, the autumn and the year. In this area, November 2011 was the 2nd mildest since before 1900, the autumn (September, October and November) was also the second warmest since 1900. Currently the year 2011 is also the 2nd warmest since 1900! So, what does December need to make it number one. The year to beat is 2006. January and February were actually milder this year than in 2006 by about 1.5 degrees. The spring was much warmer this year by about 3 degrees. However, the summer was much cooler by almost 4 degrees. This autumn was less than a degree cooler than the autumn of 2006; so where does that leave the last month of the year. December 2006 was mild with a mean temperature of 7.7 Celsius. In fact, that made it the 5th mildest December since 1900. For 2011 to be the warmest year since 1900 this month needs to have a mean temperature of 8.6 Celsius. In December 1974 the mean temperature was 8.7 Celsius so the figure is achievable, but this year? No, pretty unlikely, second best again!

Another mild and sunny day

November 2010 was a fairly dry month, but that is the only weather feature it shared with this November. So far this month there have been no air frosts, although tonight could change that statistic. There have been several mild and sunny days, a continuing characteristic of this autumn, and although the leaves have fallen off most of the trees, the run up to winter is very different from last year. On this day in 2010, it was cloudy, not unusual of course, but the maximum temperature was only 1.4 Celsius. That is 12.7 Celsius lower than the highest temperature recorded today. Although a frost is a possibility for tonight, the minimum will undoubtedly be several degrees higher than on the corresponding night last year. On that night the temperature fell to minus 5.9 Celsius, the lowest November reading for 21 years. On the last day of the month there was heavy snow, and the good folk of this area awoke on the 1st of December to an 8 centimetre covering of snow! Not so this year, presumably.

The Fog Myth

The fog which descended over parts of London and persisted through much of Sunday helped to fuel the myth that London is a foggy city. Certainly the pea-soupers that plagued the Capital in the past justifiably gave the city a bad reputation. The polluted fog of early December 1952 was probably responsible for over 4000 deaths in Greater London and this eventually led to the Clean Air Act of 1956 and a decline in the instances of choking fogs. Nowadays, the heat island of London helps to reduce the number of 'natural' fogs and the few fogs that do occur are usually confined to, or are at their worse in, low-lying suburban areas of London. The statistics for Morden show that since 1988 November, on average, has been the foggiest month. However, a day with fog (defined as a day when visibility is below 1000 metres at 0900 UTC) has only occurred on 19 occasions, and the highest number of foggy days in any month has only been 4. Thus the 'foggy London' tag has well and truly been laid to rest.

What about the frost?

This autumn, so far, has seen a couple of white grass frosts (in October) but no air frosts have occurred. How unusual is that? At this site records began in 1988 and since then there have only been 2 instances where the autumn months, September, October and November, have been completely free of air frosts. The years in question were 1994 and 1999. In 1994, November was exceptionally mild and currently stands as the mildest November in this area since before 1900. Also the temperature difference to the next mildest (1938) is, in statistical terms, quite substantial. However, at the moment, this November is milder than that of 1994, also by quite a significant margin. Today may help to change that, though, with the maximum temperature struggling to achieve double figures. In both 1994 and 1999 the frost-free period did not extend through the remainder of the year. In 1994 the first frost of the 'winter' occurred on December 15th with the 14th seeing the first frost in 1999.

The Autumn Harvest

The 25 millimetres of rain that fell on Thursday made it the second wettest day of the year, but fortunately the dry autumn has left the soil very manageable. The potatoes have been lifted and the crop looks good, so many baking potatoes for the next few months. There is a heavy crop of carrots, but they're not particularly large and wireworm has been rather problematical this autumn. A bonus this November has been the lack of air frost, so far. There were some white ground frosts on a couple of mornings during October, but no damaging air frosts have occurred this autumn and this has allowed the second crop of figs to ripen. The wet summer in this area has led to a bumper crop of celeriac and beetroot, and netting has largely managed to keep the abundant Cabbage White butterfly away from the brassicas. So, the autumn harvest is now in, with the prospect of cabbages and sprouts for the winter months ahead.

The splendid weather has to end

Although no records have been broken, this month will be remembered for many dry, sunny and pleasantly warm days, and of course the exceptional heat at the beginning of October. At the moment it is the driest October since 1978, although rain tonight looks like changing that. October 1978, despite being a dry month, was not particularly sunny, and although days were often warm, nights were sometimes quite chilly. The cool nights have been a feature of recent temperature statistics this October, and that has dragged down the temperature averages. Therefore, it seems unlikely that this month will hold on to it's 5th warmest ranking (since 1900) . However, the 4 mildest Octobers have all occurred during the last 16 years and Edwardian or Georgian London would have been very pleased with this mild, bright and smog-free month!

Receding blue skies

After the amazingly blue skies of yesterday, the clouds have returned. Mustn't grumble, though. This October continues to be the warmest for at least a 100 years but will it last? Well, maybe! Although there have been some fairly warm days, the nights have been chilly under the starry skies. The first real ground frost of the autumn occurred last night, but although there may be some more chilly nights to come, the forecast charts suggest a much more unsettled and windy second half to the month. It should mean maximum temperatures near, or slightly above average, but with nights generally much milder than average under the cloudy skies. So, probably a top 10 spot as a mild October, but number 1 will be more difficult. The mildest October, 2001, only had a monthly minimum temperature of 4.9 (0.7 so far this month!), and there were just 9 days with minimum temperatures below 10 Celsius!

The worst summer since 1993....really?

The media have, on recent days, quoted Met Office statistics that suggest this summer has been the poorest since 1993. Undoubtedly, this is true for some parts of the country but for south London it has been the worst summer since 1988 with the summer of 1993 nowhere near as bad. Comparing the two summers we find that in June 1993 the mean temperature was 16.9 C with only 9 days when maxima failed to reach 20 C. There were 5 days with highs above 25 C. Rain fell on 11 days and totalled 42.6 mm. In June 2011 the mean temperature was 15.4 C with 16 days below 20 C and only 3 days above 25 C. Rain fell on 17 days and totalled over 81mm. The July figures are 17.0 and 16.4 C; 10 versus 12 days below 20 C, but 3 against 2 days over 25 C. Rain fell on 16 days in 1993 but only 12 days in 2011. However, the total rainfall was 46 mm in 1993 and 52mm in 2011. With one day to go, August 2011 looks like being a warmer month than August 1993. 16.4 against 17.2. However, the mean maximum temperatures were similar on 21.4 C. In 1993 there were 8 days with maxima below 20 C but there have been 10 this year. There were 3 days with highs above 25 C in 1993 and also in 2011. Rain only fell on 5 days in August 1993 and totalled 30 mm, but August 2011 had 18 rain days totalling 67 mm. It's no contest. In this area the summer of 2011 has been infinitely poorer than that of 1993!

Summer coming to an end

Like it or not summer is coming to an end, at least meteorologically speaking. The 3 calendar months, June, July and August constitute summer but hopefully there will be plenty more 'summer-like' days to come during the autumn. With 10 days left until the end of the month it looks, assuming that there will be more than 10mm of rain before the 31st, as if this summer will be rated as the poorest since 1988. So how poor was that summer compared to this one. Firstly, in June 1988 there were only 25mm of rain against 82mm this last June. There were only 9 days with rain falling but in June this year there were 17 rain days. However, in June 1988 there were 18 days when the temperature failed to reach 20 C., but this year there were only 16 cool days. In July 1988 there were over 65mm of rain measured compared with 52mm this year. The rain fell on 17 days in 1988 but only on 12 days this year. There were 15 days with maxima below 20C in 1988 but only 10 days this year. August 1988 was not wet, just 29mm recorded but temperatures failed to reach 20C on 9 days. So far this month we have had over 30mm of rain but temperatures have only failed to touch the 20C mark on 3 days. It's still possible that this summer will descend to the level of 1988, but probably not.

Time for Harvest

It's the time of plenty. What ever the weather has thrown at us in the Spring and Summer, there is usually a happy ending in some form for the farmers and gardeners. In this particular area there is a fine crop of Victoria Plums, although several have rotted on the trees, and the same applies to the apples. The exceptionally dry Spring seems to have had little impact on the fruit and vegetables, but the early summer rains have been more influential. On the positive side, apples, pears and potatos are very large this year. On the negative side, there are plenty of maggots in the apples and many are falling off early. The tomatoes are poor this year, but cucumbers are good. Onions, peppers and chillies are also good, so overall it has probably been a bountiful year. Crab apples are in abundance, so hopefully there will be a return of the Fieldfares this winter. Does it mean another severe winter? One thing for sure, the fruit and vegetables are products of the past weather, and NOT the future weather!

Downhill to Autumn?

Yesterday, Saturday 6th August, is not a date that rings many bells in the weather fraternity. However, for this little part of south London it is, on average, the warmest day of the year. Okay, so the records only go back 23 years, and it is only warmer than the next warmest day by 0.1 Celsius, but the fact stands. Historically, the early part of August has seen some of the highest temperatures. On August 9th 1911 it was very hot across London, and although some of the maxima on that day were recorded in non-standard conditions, values of 38 were measured at Greenwich, 37 at Isleworth, and 36 at Camden Square, Epsom and South Kensington. However, at Kew, the maximum temperature recorded in a standard Stevenson Screen was only 34.3. Record-breaking heat occurred on the 3rd August 1990, and although only 35.5 was recorded here, there were highs of 36 and 37 in the London area. All these hot days were eclipsed on the 10 August 2003 when this site had a maximum of 36.7 and areas in. and around, London had highs around 37 or 38. This was the hottest day since instrument records began, and on an afternoon when the temperature is failing to reach 20 it seems a far distant memory.

So, how bad is this summer?

The summer is about two thirds over and there are two schools of thought as to how it is progressing. Some think it is very pleasant with good growing weather. Others think it is cool and wet. Statistics point towards the latter claim....but with reservations! It has been said many times that the manipulation of numbers can often produce the results you want to see and the following figures come with the same caveat. By using a ranking system from 1 to 112, with 1 being the warmest or driest since 1900 and 112 being the coolest or wettest since 1900, comparisons can be made. For example, June and July 1976 were both warm and dry. Using equal weighting, June 1976 produce 1+6=7 and July gave 8+16=24. The total therefore was 31. By way of contrast, the June and July of 1987 were both very poor and produced 86+86=172 for June and 56+92=148 for July, a 2-month total of 320. So far, the numbers for June are 67+94=161 and for July 90+59=149, a total of 310. It can be seen that using basic comparisons of temperature and rainfall, the first 2 months of this summer are up there with the worst of them! Let's hope that August 2011 is less forgettable than the early months of summer.

Wet, but could be wetter!

As the rain hammers down again, it looks as if the monthly average for July could be exceeded by the end of today. In recent years there have been several quite wet Julys. In 2009 measurable rain fell on 22 days, and in 2007 over 124 mm of rain fell, including the 41mm that was recorded on the 20th. Some of the most intense rainfall of the year can fall in July, and large totals over a very short time period are not that unusual. Kensington had 25 mm of rain in 12 minutes on the 11th July 1927, and on the same day 37 mm fell in 18 minutes at Balham. On the 26th July 1946 there was a fall of 50 mm in 35 minutes at Kew. Some parts of Greater London have had over 100 mm in 24 hours and southeast London appears to be particularly vulnerable to these heavier falls. Over most of London it looks as if 1918 had the wettest July with parts of southeast and east London recording over 200 mm of rain. West London fared better with only 121 mm of rain at Kew, a figure this month is moving towards; but will it reach it?

A touch of optimism for July, maybe!

The general consensus is that this July has been poor so far. Statistics bear this out, with rainfall (up to the 10th) already 50% of the monthly average and temperatures the lowest for 23 years. The month has a long way to go and changes may occur. In some years they are marked. For example, in 1980, after a cool and wet June, holiday-makers were hoping for a better July. Alas, the first day of the month brought strong northerly winds, persistent rain and drizzle and a high of only 15. At midday in central London the temperature was only 12! A couple of dry and warmer days were then followed by more rain, and on the 8th another very cool, windy and wet day occurred with the 9th little better. No let up in the unsettled weather occurred until after mid month with infrequent sunshine and afternoon temperatures typically between 14 and 17. Finally, a sunny day occurred on the 21st, and although the maximum was only 19, it was the beginning of a spell of summery weather that lasted until the last couple of days of the month. On the 25th the temperature reached 28. Despite the warm end to the month, July 1980 was the coldest since 1922, and in recent years, although poor Julys have occurred, none of them have approached the dire weather experienced during the first 3 weeks of that very forgettable month.

July, the best summer month?

It can be argued that July is the best month of the year even though many of the high temperature records have occurred in August. Looking at the statistics for Morden, these covering the last 22 years, it would appear that day-time temperatures for July are 0.2 degrees warmer than those for August (23.3 against 23.1). Rainfall is 12mm less in July compared with August (43 against 55), in fact in recent years July averages out as the second driest month of the year behind March. All the summer months, along with May, only have 11 days with significant rainfall (0.2mm or more), but it's the subtleties that make July the best month. It hasn't the same number of very chilly days that can often spoil a June (Only 2 of the last 22 Julys have had maximum temperatures below 16, yet 17 Junes have had chilly days including a high of only 11.8 in 1998). August has had 2 years with maxima of 16, but in most years there is a distinct feel of autumn late in the month as the heat from the sun becomes less apparent. So, that's the argument for July, and today is a perfect example. Light winds, a mix of clouds and sun and a temperature of 24. Unfortunately, by Wednesday we'll be seeing the bad side of July weather!

3 fine days and a thunderstorm

George the Second (1683-1760) was unique in many ways. Firstly he was the last monarch to be born outside of the United Kingdom, secondly he was the last monarch to lead a British army into battle, and thirdly he was considered to be responsible for the adage that a British Summer was '3 fine days and a thunderstorm.' By co-incidence, a long-standing rainfall series for England and Wales commenced in 1727, the same year that he succeeded his father as king. During his reign he probably became aware of some exceedingly wet summer months. 1736 produced one of the wettest Julys ever known, and the Julys of both 1743 and 1751 were also thoroughly wet. Some wet Augusts occurred in the early 1730s, but perhaps it was the extremely wet August of 1737 that triggered the quote. We may never know, but there is certainly some truth in the saying, and as we enter day 2 of the fine spell (and the warmest day of the year so far!) , we wonder if the hot and humid day tomorrow will be followed by that traditional thunderstorm!

Good for the garden...in moderation!

Rain is almost a daily occurrence this month, and although it has done wonders for the garden, it is now becoming somewhat excessive. So far, this June has had nearly 66mm of rain making it the wettest this century. It has a long way to go before beating the 137mm that fell in June 1997. Nevertheless, there has almost been twice as much rain as we had in the whole of the Spring (March, April and May). Whilst the fruits are filling out quite nicely, the temperature is on the low side for some crops, especially tomatoes. At the moment it is the coolest June for 20 years, although there is a hint of somewhat warmer weather later in the month. The highest daily average temperature occurred in April with 19.3C. May had 18.6C, and so far this month the average is 19.1C. It would be extremely unusual if this situation was unchanged at the end of the month, and it would be even more unusual, perhaps unique, if the highest temperature (27.2C on the 23rd April) turned out to be the warmest day of the year!

Rain, and more rain

With the drought stories fading from the news as quickly as they appeared, rain drops continue to fall. Of course, some parts of the country are still in dire need of sustained rainfall, but for this area of south London the drought is well and truly broken. So far this month we have had over 45mm of rain. Already it is the wettest June for 4 years, and the wettest start to June since 2002. In that year 42mm fell in just 1 day (the 5th), and back in June 1973 nearly 45mm fell in Morden in 1 day. Recently, Junes have tended to be dry and there have only been 2 wetter than average June since 2000, Prior to that, there were a couple of exceptionally wet Junes. In 1998 nearly 125mm of rain was recorded, and in the previous June (1997) over 137mmwas measured. Although 1997 possessed the wettest June in living memory, in 1903 over 180mm of rainfall was measured at Kew, all of it falling between the 9th and 20th. At Carshalton over 80mm of rain fell on 10th June 1903. By the way, most of the rest of that Summer, and much of the Autumn, remained cool and wet!

1976 and all that

The grass is beginning to turn brown quite widely, just as it did during the summer of 1976. If the media were to believed in those hot and dusty days England would never again be a green and pleasant land. Of course, the rain arrived in spades late in August and through September. By the end of autumn, there was little to show for the prolonged dry spell. Aside, that is, for a few dead trees, most of which weren't native to southern England. So, where does it leave 2011? Although, it was the driest Spring this year in living memory and beyond in this area, the winter was fairly wet. Already this year we've had over 50mm more rain than we had in the first 6 months of 1976. Also, the weather patterns showed marked differences between the Springs of 1976 and 2011. As a result temperatures are very different. March 1976 was cooler than March this year with no days exceeding 16 Celsius (5 this year). April 1976 had near normal temperatures compared to the record-breaking warmth this year. By way of contrast, May was fairly warm in 1976 with the temperature exceeding 29 Celsius as early as the 7th. Although this May was reasonably warm there were no hot days. June 1976 was outstandingly warm, and although the maximum temperature today is around 27, a decline into maxima mediocrity seems imminent.

The dry Spring

Less than 72 hours until the end of Spring. For rainfall purposes it ends at 0900GMT on June 1st. At the moment another 6mm of rain are needed to keep the old 1976 record intact. The thunderstorms on Thursday produced over 8mm of rain and that made it the wettest day since January 17th. There was rain at other times last week, but although fronts brought changes of airmass, amounts of rain were negligible. The 'record' now appears to hinge on the behaviour of a minor wave on a cold front currently to the west of the UK. Computer models suggest that this wave will become quite active as it trundles northeast over southern England tomorrow. At the moment, it looks as if the heaviest rain will occur west and north of London, but in addition to this frontal rain, destabilization ahead of the front tomorrow may lead to showers breaking out, although the near continent seems more at risk from that feature. It certainly looks like being a close run thing before Summer begins ..... with the prospect of further records??

Dry, but getting wetter!

The 23rd of May, the sun is shining, but rain over the weekend has reduced the Spring deficit and it remains uncertain whether the 'record dry Spring will become a reality. A mere 15mm will now take the 3 month total past that achieved in Spring 1976 but there are only 9 rain days left! Let's have a look at the latest charts. At the moment the radar shows a band of rain over Wales and that's forecast to weaken considerably as it moves southeast. Probably 1mm at most before it clears. Tomorrow (24th). Only an outside chance of a shower. 25th suggests a weak front late in the day or overnight, again less than 1mm. So, 6 days to go and 13mm. 26th will probably be showery, typically 2-5mm, with a ridge of high pressure helping to produce a dry day on the 27th. The 28th could well be a wet day 5-10mm, possibly more! Back to showers and around 2mm on the 29th followed by more substantial rain on the 30th (5-10mm) and then showers again on the 31st (about 2mm). Best estimate would suggest the record will be missed by close on 3mm. Bad news for the thrill-seeking statisticians. Great news for the gardeners!

Now it's seriously dry.

A few spots of rain fell this morning but now it's beginning to look very dry. The trees are losing their Spring lustre and the grass is turning increasingly brown. It's not surprising really. The total rainfall for this area since 1st March (66 days) is only 21.6 mm. To put that figure into context, the 20-year average fall for those 66 days in this area is 105mm, so the total this year is only just over 20% of the average. What of the rest of Spring? Will it beat the record? Interestingly, the average rainfall for the first 15 days of May is 15mm, but for the last 16 days of May the average is 29mm. Therefore, if 'average' rainfall occurs for the last 16 days of the month the record will not be broken! The total for the Spring would then be around 51mm which would rank this Spring as the 6th driest since 1900. However, if only 18mm of rain falls the record will be broken. In 4 of the last 20 years, and 21 of the last 110 years, there have been daily falls of over 20mm in this area during May. So, it only takes one big thunderstorm and that 'Dry Spring' record set in 1976 remains intact.....and by the way, the grass really did turn brown by the end of that Summer, all of it!

Not enough rain.....yet.

The heaths around London were tinder dry after weeks without significant rain, but west of London there were 9 or 10mm of rain during Saturday with parts of west Surrey having several millimetres more than that. Unfortunately most of east Surrey and south London had considerably less rain with typical totals 2 or 3 mm. In this part of south London the total rainfall since 1st March is only 21mm, still 19mm short of the 40mm that is needed to prevent Spring 2011 being the driest since before 1900. So, just 24 days left before 'Summer' arrives and will the record be broken. Obviously too early to say yet, and in showery weather totals can increase quickly. However, over the next few days it looks as if showers will be few and far between in this area, and although the further outlook remains generally unsettled, whilst the main area of cyclonic activity stays to the north of Britain, the prospect for substantial rain in south London stays small.

April 2011....a remarkable month

April 2011 was a sunny month, about the 15th sunniest since 1900. It was also a dry month, the 2nd driest since 1900 behind the April of 1938. It was also the driest early Spring (March/April combined) since 1938. However, the most remarkable feature about April 2011 was the temperature. It was the warmest April since reliable instrument records began in the 19th century, and in doing so beat the outstandingly warm April of 2007. To put the event into perspective statistically; the mean temperature for April 2007 was 13.0, which was a massive 1.4 Celsius higher than the previous record set in 1943. The mean temperature for April 2011 was 13.6! If the month was May instead of April it would have been ranked the 21st warmest May since 1900. The very dry ground aided overnight cooling, and although no air frosts occurred, the mean minimum temperature was only 2.5 Celsius above normal. The mean maximum temperature (19.3) was 4.9 Celsius above normal. This figure was truly incredible. Since 1900, there have only been 8 Mays with higher average maxima. None of these warmer Mays occurred between 1923 and 1988 inclusive. Not only were April 2011 days warmer than most May days, there were several summer months in recent years that have been cooler by day: namely the Junes of 1953,1954,1955,1956,1971,1972,1977,1978,1979,1980,1981,1985,1987,1988 and 1991: the Julys of 1954 and 1980; and the Augusts of 1956 and 1963. What next?

A mild February. Nature redresses the balance.

Although cold air continues to lurk uncomfortably close on the near continent, forecast charts for the remainder of the month generally suggest that mild weather will prevail. In fact the projected mean temperature in this area of 7.8 Celsius would rank February 2011 as the 4th mildest in the last 110 years, behind 2002, 1990 and 1961. In February 2002 there were no exceptionally mild days, but only 2 air frosts occurred in this snow-free month. In February 1990 there was sleet early on the afternoon of the 3rd, but only 1 air frost occurred and on the 23rd the afternoon temperature soared to a record-breaking 19.0 Celsius. In February 1961 there were several very mild, sunny days and the month was totally free of air frost and snow. Although this February is not going to be a record breaker it has certainly helped to redress the balance after the cold December.