The UK in September
Mike Hulme on last month’s weather
DAYTIME TEMPERATURES
September was a cool month,
daytime temperatures during the middle of the month dipping to more than 3C
below the seasonal norm. The only
region to exceed average temperatures was the south of England and even here
only by a few tenths of a degree.
Elsewhere, Birmingham and Scarborough recorded average monthly daytime
temperatures nearly 2C below usual. The
warmest days were the 1st of the month and the 28th, the
latter coinciding with a deep southerly airflow that also brought rain with
it. Following a reasonably warm late
spring and summer, the year 2001 in the UK is still averaging just above the
long-term average. Worldwide
temperatures continue to be well above the 1961-90 average and 2001 will
continue the long sequence of globally warm years.
RAINFALL
Rainfall was patchy during
September, although a wet final week saw the nationwide total for the month
reach 89% of the long-term average. The
eastern coastal regions, especially East Anglia, were the wettest in relative
terms, Lowestoft recording over 120mm of rain, more than double its September
average. Folkestone, Skegness,
Scarborough and Aberdeen were also wetter than usual for this time of
year. The south of England, Wales and
northern Scotland were generally dry, rainfall in the southern counties failing
to reach 50% of average. There were no
really dry spells during September and, curiously, the wettest days in the month
all occurred on either Tuesdays or Wednesdays.
The very wet late winter/early spring period means the year as a whole
remains wet.
SUNSHINE
Although September overall
was rather dry, it was also a cloudy month with sunshine totals on the low
side. The southern counties recorded
the best of the sunshine, but Tiree in the Western Isles also was sunny and
recorded 38% more sunshine than is usual for September. The best of the sunshine occurred during the
first half of the month, the sunniest day being the 8th. Not surprisingly, with much of the rain
falling around the eastern coasts, places like Lowestoft and Scarborough
recorded the lowest sunshine totals.
Dr Mike Hulme is at UEA and
is a Director of the Tyndall Centre for Climate Change Research.
(more details at website at
www.tyndall.ac.uk)
September 2001: Cool; wet in the east
Daytime Temperature: 0.5C below average; Rainfall: 11% below average; Sunshine: 10% below average.
[all average figures are
based on the 1951-80 average]
Mean monthly extremes:
Warmest Bournemouth 19.1C
Sunniest Guernsey 196 hours
sun
Wettest Morecambe 167mm
Coldest Lerwick 11.9C
Cloudiest Kinloss 67 hours sun
Driest Guernsey 16mm