The UK in December

 

Mike Hulme on last month’s weather

 

 

DAYTIME TEMPERATURES

December was clearly a month of two contrasting halves - the first two weeks being extremely mild with daytime temperatures up to 4C above average and the last two weeks seeing temperatures fall by up to 10C.  The month as a whole remained milder than is average for December, more so in the south and east than in the north and west.  The last week of the year was the coldest in the UK since January 1997 and in some regions the coldest since 1987.  The final estimate for the year 2000 was that the UK was about 0.5C above the long-term average - only 1993 and 1996 have been cooler than this average during the last decade.  The decade as a whole has been about 0.6C warmer than the 1961-90 normal.

 

 

RAINFALL

Although temperatures fell as December progressed, for the most part the rainfall continued, although in the week after Christmas this turned to snow for most regions.  This was the fourth consecutive month with exceptionally high rainfall totals in the UK, December averaging about 60% above the normal, quite similar to December 1999.  The west country was the most anomalous with well over two times the December average being recorded.  In contrast, Skegness and Lerwick in the east and north were a few millimetres drier than usual.  The wettest day of the month, and second wettest of the year, was the 8th with a nationwide average of 15mm falling. 

 

 

SUNSHINE

The interesting trend of very wet, but sunny, months in the UK continued.  Following October and November, December 2000 was also about 9% sunnier than average across the country.  This was due mainly to higher sunshine totals in the south, east and north - locations in the west like Anglesey and Belfast barely managed an hour of sunshine per day, 25% or more below the normal.  The sunniest day for about 2 months occurred on the 30th December with a nationwide average of 4.7 hours of sunshine.  Six of the last seven Decembers have been sunnier than average, only 1997 interrupting the sequence.

 

 

Dr Mike Hulme is a Director of the Tyndall Centre for Climate Change Research, at UEA

(more details at website at www.tyndall.uea.ac.uk)

 

 

December 2000: Very wet, mild at first

 

Daytime Temperature: 0.6C above average;          Rainfall:   63% above average;    Sunshine:  9% above average.

 

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

 

Mean monthly extremes:

 

Warmest          Guernsey                                        11.3C

Sunniest          Folkestone                                      69 hours sun

Wettest          Eskdalemuir                          328mm 

Coldest          Lerwick                                   6.4C

Cloudiest          Lerwick                                   19 hours sun

Driest           Skegness                                        53mm