Expert comment: driest start to a winter in century

The first half of December has been the driest ever in more than a century of records from the University of Reading Atmospheric Observatory, meteorologists say.

The cold snap continued overnight as yet more minus temperatures were recorded, making this past week the coldest week of sub-zero temperatures for more than a decade.

Dr Stephen Burt, Visiting Fellow at the Department of Meteorology, said that data from the Atmospheric Observatory was showing the coldest week since 2010, and a lack of precipitation in December adding to concerns about longer-term drought.

Meteorologists have been recording conditions at the University’s weather observatory consistently every day since 1908.

Dr Burt said: “Friday morning's (16 December) minimum temperature in the Observatory was minus 5.7 °C. This makes the third '-5.0 °C. ' morning we've had so far this month, and takes the mean temperature for the week, up to 15 December, down to -1.3 °C.

“This is 6.8 degrees below the December normal of +5.5 °C and the coldest week of any on the University's records since Christmas 2010.

“It's not surprising that focus has been on the low temperatures, but let's not forget precipitation. We've had the driest first half of December on our record, which goes back to 1908. We'd normally accrue about 27 mm of rainfall in the first fifteen days of December, but to date we've recorded only 0.2 mm, less than 1% of normal.

“Our previous driest first half of December was exactly 100 years ago, when in 1922 just 0.7 mm fell 1-15 December, a value equalled in 2004. This comes at the end of what has been a very dry year, although the wet and mild November saw some recovery in reservoir and groundwater stocks.

“If the rest of the winter should remain dry, next spring could see the return of water restrictions in affected areas.”