Wednesday, 29 August 2012

.....and now September!!


As August draws to a close many people have probably forgotten how bad the early part of the Summer was. Fortunately, this month has redressed the balance somewhat, and as the reasonable weather has  coincided with the Olympic Games, as well as the school holidays, the grumblings have largely ceased. Nevertheless it still looks like being around the 5th or 6th wettest Summer since 1900. Interestingly, the two wet Summers nearest in rainfall totals to this Summer were in the years 1912 and 1958. The Septembers that followed these wet Summers were not lacking in weather events. In 1912, September was the second coolest between 1900 and 2011 with no days having maxima above 19 Celsius. As early as the 11th the temperature only reached a very cool 11 Celsius. In September 1958 the weather was fairly warm, especially early in the month, but overall it was wet, actually the 9th wettest since 1900. However, it was notable for some violent thunderstorms in southern Britain. After a warm and humid day on the 5th, storms broke out and in one of these storms near Horsham (West Sussex)  giant hail fell. The 'stones' were variously described as the size of grapefruit or tennis balls and one weighed in at 140 grams!  Now what does September 2012 have to offer? We keenly await!

Sunday, 24 June 2012

The other 2 awful Junes

There is the prospect of somewhat better weather during the last week of June, even the chance of temperatures into the high 20s on Thursday. However, overall it still looks like being the 3rd worst June since 1900. The 2nd worst June, 1971, had a mean temperature of 13.5, a value that will be exceeded this June, and it also had 131 mm of rain, a figure that could be exceeded if heavy rain accompanies thunderstorms at the end of the mini heatwave on the 28th. Interestingly, although sunshine amounts were well below average it was not amongst the top 10 dullest Junes. It was a long time ago! Production of the Morris Minor ceased in 1971, decimal currency was introduced and in June the Chancellor of the Exchequer, George Osborne, was just a few days old. June 1903 was  arguably the worst June since 1900. The mean temperature was 13.2, and in southwest London 183 mm of rain fell. It was a dull month, although nowhere near record breaking. The total sunshine for the month was 184 hours, a figure that is unlikely to be reached this month.  In the year 1903 the Daily Mirror was  first published; six years later a rival paper, the Daily Mail, warned that Germany was preparing to destroy the British Empire. The June of 1909 was easily the dullest since records began with only 105 hours of sunshine. So far this June there have only been 87 hours of sunshine, but Germany is a much more generous player on the world stage than in those gloomy days.

Monday, 11 June 2012

How bad is this June? (so far!)


Flash flooding and grey cheerless skies are grabbing the headlines, but how bad has this June been so far? With one third of the month gone it is the 8th coolest June since 1900 and the coolest in the area for 35 years. Already it is the 19th wettest since 1900 and the wettest in Morden for 14 years. If the coolness of the month and the wetness of the month are combined, and given equal weighting, it is currently the 6th worst June since 1900. and the worst June in this area since 1991. The top 3 inclement Junes were 1909, a very cool month in which the temperature failed to rise above 11 Celsius on the 6th and it was the 3rd coolest June of the century. It was wet with 87 millimetres of rain falling, although there were 14 dry days. Number 2 was June 1971 when over 130 mm of rain fell at Kew and for parts of the south coast between Devon and Sussex it was already the wettest June on record by mid month! Ironically, for many parts of the country the first week of June was dry and pleasantly warm. The June of 1903 was the wettest of the century with 183 millimetres falling at Kew. Actually, on 20 days no measurable rain fell, however sunshine was in short supply and, apart from a few days at the end of the month it was decidedly chilly. What of sunshine this June? At Heathrow it is averaging just over 2 hours a day, and if this is figure is maintained until the end of the month it will easily be the dullest June on record. However, this poor weather is unlikely to last until the end of the month. Just like the economy, it will improve with time, won't it? 

Sunday, 29 April 2012

Don't mention the drought!

At the time of writing it only needs one thundery downpour to make this the wettest April for well over 100 years. Looking at the 10 wettest Aprils since 1900 there are hints that wet Aprils do not bode well for the following summers.
10th wettest April, 1907, was followed by a persistently cool summer with no temperatures exceeding 25C. June was wet but the other summer months were drier than average although the weather remained unsettled.
9th wettest April, 1918, was followed by a cool June, a fairly cool and very wet July, and a rather dry August with temperatures only slightly below average.
8th wettest April , 1981, was followed by a cool, but rather dry June, a rather cool but fairly wet July, and a reasonably dry and warm August.
7th wettest April, 1964, was followed by a cool and wet June, a decent July and an average August.
6th wettest April, 1998, was followed by a wet June with near average temperatures, a dry, but rather cool July, but a dry and warm August.
5th wettest April, 1924, was followed by a cool and wet summer with June and July being particularly wet.
4th wettest April, 1966, was followed by a near average June but the rest of the summer was mostly cool and wet.
3rd wettest April, 1931, was followed by a reasonable June but a poor July and a poor and particularly wet August.
2nd wettest April. 1983, was followed by a good summer with plenty of dry weather and an outstandingly warm July.
Wettest April was 2000  and was followed by a pleasant June, a cool July and a reasonable August.
Overall, out of the 10 years there were only 3 acceptable summers, although one of these was exceptionally good.

Sunday, 15 April 2012

A cold April for a change

It's now half way through the month and there is every indication that we are in for a colder than average April. In fact it could be the coldest April since 1989 although a lot can happen in 2 weeks! In recent years we have had many warm Aprils. Last year there was record-breaking warmth during April and, excluding this month, the 3 warmest Aprils since 1900 have occurred in the last 5 years. Looking at the top 10 coldest Aprils in this area since 1900 the only ones in fairly recent years that have featured are 1986 and 1978. Most of the top 10 (6 entries) are made up of Aprils from the first 30 years of the 20th century. The coldest April of all was 1917. To put that April into perspective, the mean temperature was 6.0 Celsius, compared with 8.2 Celsius so far this month (last April, 2011, we had a mean temperature of 13.6 Celsius). It looks as if both the April of 1917 and this month were/are showery months, but it was noticeable that up on Hampstead Heath there were 13 days when sleet or snow was observed and grass frost occurred on 26 nights. So, the air was obviously cold, and in that year the temperature didn't rise above 15 Celsius until the very last day of the month. We' already had 16C!!

Sunday, 8 April 2012

How bad is the 'drought'?

Now the hose-pipe ban been implemented the rain has started to fall, albeit in small amounts, so far! Comparisons have been made with the 'drought' of 1975/6. Comparing the rainfall figures for Kew in 1975 and Morden 2011 the totals are as follows:- Annual total Kew 1975 was 558mm. Annual total Morden 2011 was 510mm. Total from July to December (Kew) 1975 (6 months) 263mm (this included 51mm in just 1 day during September!). Total from July to December (Morden) 2011 (6 months) 268mm. For the last 3 months of 1975 the total was 108mm, in 2011 it was 123mm. The first 3 months of 1976 produced just 46mm. January to March this year has given 73mm. The '75/76 drought did not really become serious until the summer months of 1976 when days of unbroken sunshine accompanied by brisk winds, heat and low humidity conspired to reduce reservoir levels dramatically. Yes, some of the reservoirs this year are down below 50% capacity, and yes leaks from pipes are unacceptably high, but it remains to be seen if the the widespread ban on hoses is a justified precaution against water shortages, or a cynical political ploy to soften us up for the compulsory use of water meters!

Sunday, 25 March 2012

Mildest March?

At the moment this is the 6th mildest March since 1900 and by the end of the month it may climb to number 4. However, the 3 mildest Marches are unlikely to be bettered this year so, at best, it will be the mildest March since 1997. In that year it was dry, drier than this March, with only 11mm of rain. The highest temperature was only 17.5C and there were 9 days when the temperature was 15C or higher; this year there have been 10 days above 15C already. In 1997 there were no days in March with maxima under 10C, this year there have been 4 so far. There were no air frosts in March 1957 and there have been 2 so far this month. And April 1997? Unfortunately it was another dry month with 12mm of rain and no significant rain from 25th March to 17th April (24 days). The other 2 very mild Marches were firstly 1957, a rather dry month with the temperature rising to 19C and with only a couple of slight frosts. This was also followed by a very dry April; and secondly the other mild March was in 1938. The highest temperature was 18C and it was a very dry month followed by an even drier April. In that year no rain fell between 2nd and 24th March (23 days) and between 4th and 23rd April (20 days). Statistically it doesn't look good for when the hose-pipe ban commences!