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