Martin Rowley wrote:
Subjectively, the last three months (November & December 2010, January
2011) have been noteworthy for lack of sunshine in this part of the
country.

At Hurn, the Kipp & Zonen sensor (KZS) has been in use since May 2004,
replacing the Campbell-Stokes recorder (CSR) record which began in
December 1968. There are published 'factors' which attempt to relate
both instrument's output, though with no lengthy overlap period, all
deductions have to be hedged about with caution.

The approximate monthly %ages, resolving the KZS values to a pseudo
CSR record for these three months (November, December 2010 & January
2011) are 78%, 53%, 85%; December was possibly the dullest or
second-dullest such-named month in that record.

The total sunshine by the current [KZ sensor] for November, December &
January = 134 hr: crude relation to CSR climatology (1971-2000) 73%.

Over those three months, on 44 days, no sunshine at all was recorded,
a whisker under half of the available days; there were 5 'spells' of
three or more sunless days, with a notably gloomy stretch of 11 days
from 27th December to 6th January.

In the Hurn sunshine record (Met Office web site), which runs from
1969, only one other November - January period comes close, that of
1994/95.

Martin.


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Thanks Martin. Always nice to know I've not been whinging for nothing! I
suspect sunshine figures were even lower than that here.
Dave