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!

Sunday, 11 March 2012

Spring - Full steam ahead

Just when it looked as Spring was going to be late this year the weather changed and Spring is accelerating forward. It has not been unusual in recent years for nature to get a big boost from March warmth. In the last 23 years the mean temperature for March has been 8.0 Celsius. Prior to 1989 this figure had been exceeded on only 13 occasions since the year 1900. Since 1989 there have been 14 occasions when March has had a mean temperature higher than 8.0 Celsius. So far this March (excluding today) the mean temperature has been 8.2 Celsius but the forecast charts suggest it may eventually be much higher than that. To claim a 'top ten' position the mean temperaturee has to be 8.7 Celsius or higher. This figure was last exceeded in March 2003 with a mean temperature of 9.0 Celsius. This placed March 2003 at number 6 in the list dating back to 1900. The one to beat is March 1957 (9.9C). On this day in 1957 the temperature in London exceeded 19 Celsius and even the coldest day of the month had a maximum temperature above 9 Celsius. The month was not frost-free, though. On the morning of the 4th a temperature of minus 1 Celsius was recorded.