April 2012 early statistics – above average rainfall

These are early figures covering 1 – 25 of April and not full month statistics, so are therefore very likely to change. Especially regarding ranking. Full month figures will not be available until provisionally Wednesday 2 May.

Figures for 1 – 25 April show the month so far has seen well above average rainfall across the UK, with 97 mm of rain recorded – this is 139% of the long-term monthly average (1971-2000). The wettest April in the records dating back to 1910 was 2000 which saw 120.3 mm of rain.

Currently the month is the 9th wettest April for the UK in the records. However, it’s not possible to say where the month will end up in the records until all the figures are in at the end of the month – especially as we are expecting heavy rain on Sunday.

Some areas have seen significant rainfall amounts with some parts of the UK already having had more than double their monthly average. Some station records are also very likely to be broken.

Impact on drought

Looking at the England South area, which has been the focus of the current drought, this month is one of only three in the last two years which has seen significantly above average rainfall.

As can be seen from the chart below, the majority of other months during that time have seen below average rainfall.

Monthly rainfall anomalies for region England south for the last 3 years. 13 of the last 24 months have seen less than 75% of average rainfall, and 6 months have seen less than 50%. Only 2 months - June 2011 and August 2010, have been significantly wetter than average.

Trevor Bishop, Head of Water Resources at the Environment Agency, said: “it’s going to take more than a week or two of rain to undo the effects of nearly two years of below average rainfall.

“More rain now will really help us get through the summer, and is good for the environment, farmers and gardeners, but it’s very unlikely to be enough to recharge the groundwater.”

Duller and slightly cooler than average

Temperatures have been close to the average for the time of year, despite some cold nights towards the beginning of the month which brought frosts to many areas.

Sunshine hours have been slightly down on the average so far this month, with most parts of the country seeing only about two thirds to three quarters of the average expected in the month. However, this could improve during the final few days of April.

Why the unsettled weather this month?

The position of the jet stream has been one key contributing factor, but potentially not the only one. You can read more about this on our blog post.