How severe can the frost be?

There is much talk at the moment about severe frosts affecting this area over the coming nights. So how severe can severe be? Last night ice formed on the pond as the temperature dipped to minus 3, and ice will probably stay on the pond for several more days. If the ground remains frozen that helps nights to become colder, and a deep snow cover helps even more. Since 1991 the lowest February temperature has been minus 6.0, this being recorded in both 2007 and 2008. The lowest temperature of any month recorded at this site was minus 9.9 on the morning of February 10th 1991 over 17cm of fresh snow. Prior to that, the temperatue was almost as low in the February of 1986. The coldest Februaries overall since 1900 didn't necessarily produce the lowest minima, mainly because strong winds and cloudy skies prevailed. In 1947 a minimum of minus 9.7 occurred but the lowest seems to be minus 11.8 in February 1895. Is it there to be beaten?

There is still time!

The crab apples are beginning to rot on the trees and so far there has been no sign of the Redwings or Fieldfares that descend on the tree when there is 'real' winter weather. There still hasn't been any 'proper' snow and the days are steadily lengthening. The forecast charts occasionally hint at a blast from the east but without much conviction, although there is still hope. Some of the coldest Februaries have been proceeded by average, or even mild, Januaries. In 1947, the coldest February since 1900, was preceded by fairly mild weather up until mid January. In 1986, the second coldest February since 1900, the preceding December was less snowy than December 2011! There were just 2 days with a few blobs of sleet. January 1986 was a wet month with temperatures close to average. Sleet or snow fell on 8 days but it didn't settle. The last week of January became rather cold and winds swung to the northeast and then February! The first few days of the month were dull and drizzly although a little snow settled on the evening of the 2nd. Real winter began on the evening of the 5th. Snow fell followed by a frost, and snow then remained on the ground until the 5th March with every night during that period having a frost. Time will tell!

Frosty nights, but not exactly winter!

There have been 4 consecutive frosty nights, and the pond has been frozen solid for 4 days, but it's hardly wintery weather. There were 3 days of 'snow' during December, although the 'snow' was. in fact, sleet with a limited amount of snow flakes, so it won't be a winter free of snow. However, it's beginning to look as this month could be devoid of snow. The last January without snow was in 2002, but snow-free Januaries are not that unusual. In 1989, 1990 and 1992 January was free of snow here, but according to Brazell, London Weather (1968), 'a January without at least local snow (in the London area) is rare and there have only been 5 years since 1900. The Januaries in question were 1904,1906,1916,1925 and 1944. By way of contrast, there were 21 days with sleet or snow falling in January 1963 and the ground remained snow covered throughout the month. A January without an air frost is extremely rare. In 2008 there was only 1 air frost in Morden, but it appears that the only January without an air frost in the Morden area was 1938.

Soft January days

At the moment, with a third of the month gone, this January is the mildest since before 1900. It hasn't been wall to wall sunshine, but the soft grey clouds with chinks of blue showing through are nevertheless uplifting when accompanied by a temperature that frequently tops 10 Celsius. Since 1900, a total of 4 out of the top 10 mildest Januaries have occurred during the last 10 years and only 2 of the mildest Januaries occurred before 1974. The mildest January, 2007, had maxima above 10 Celsius continuously from the 3rd to the 20th, and on 6 days the high topped 13 Celsius, a figure we haven't reached this January. The highest value was 14.2 Celsius on the 18th, a day of destructive winds when a gust of 58 knots (64 mph) was recorded here. Although the month was record-breakingly mild, it was not without its wintery moments. Sleet or snow fell on 5 days towards the end of the month and on the 24th there were 3 centimetres of snow carpeting the garden for most of the morning.

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!