The UK in December

 

Mike Hulme on last month’s weather

 

 

DAYTIME TEMPERATURES

Although the first 10 days of December were milder than usual, the rest of the month was cold and by the end of December daytime temperatures were the coldest of the whole year.  Each of the last three days of the month averaged below 3C during the daytime, colder than the previous 2001 cold snap of early March.  Only the far western isles of Scotland escaped this cold weather; Tiree, for example, ended up about 0.4C warmer than normal.  The most unusually cold locations were in central and southern England, Birmingham being nearly 2C colder than the norm.  For the UK as a whole, daytime temperature during 2001 ended up averaging very close to the long-term normal.

 

 

RAINFALL

December was the second successive dry month in the UK, rainfall across the country only averaging about 66% of the long-term normal.  The 9th to the 15th of the month was the driest 7-day spell in the entire year, when virtually no precipitation fell anywhere in the country.  Most of England and Wales failed to record even half of their average December rainfall.  Scotland and Northern Ireland were a little wetter, but only Aberdeen, Kinloss and Lerwick of the locations monitored here reached their December average, and even then only just.  The first week of December was the wettest.  This was the driest December in the UK since 1991.

 

 

SUNSHINE

A remarkably sunny month and certainly the sunniest December in over 15 years.  The 4 days from the 9th to 12th had sunshine totals across the country more typical of early September than of mid-December, with each day recording more than 4.5 hours of bright sunshine as a countrywide average.  Only Aberdeen failed to enjoy at least the December average sunshine for the month.  Belfast and Guernsey recorded more than twice their average amount of  sunshine for the month – in Guernsey’s case this meant nearly 4 hours of sunshine per day.  The three winter months of calendar year 2001 – January, February and December – were all remarkably sunny months.

 

 

 

Dr Mike Hulme is at UEA and is a Director of the Tyndall Centre for Climate Change Research (more details at www.tyndall.ac.uk)

 

 

December 2001: Very sunny and dry; rather cold

 

Daytime Temperature: 0.9C below average;          Rainfall:   34% below average;      Sunshine:  64% above average

 

[all average figures are based on the 1951-80 average]

 

Mean monthly extremes:

 

Warmest          Guernsey                                        10.2C

Sunniest          Exmouth                                          116 hours sun

Wettest          Lerwick                                   152mm 

Coldest          Eskdalemuir                          4.5C

Cloudiest          Lerwick                                   31 hours sun   

Driest           Ross-on-Wye                               28mm