Temperature
Mean daily maximum: 10.1 (4.4 above average)
Mean daily minimum: 4.8 (4.0 above average)
Mean temperature: 7.5 (4.3 above average)
Highest daily maximum: 13.0 (18th, 19th)
Lowest daily maximum: 5.7 (11th)
Lowest daily minimum: 0.1 (13th)
Highest daily minimum: 10.1 (17th)
Lowest daily grass minimum: -2.9 (13th)
Number of air frosts: 0
Number of ground frosts: 6
Days with max 10.0-14.9: 20
Days with max 5.0-9.9: 11
Frost duration: 0.0 hours
Rainfall
Total fall: 170.6 mm (111% of average)
Wettest day (0900-0900) 30.8 mm (12th)
Rain days (0.2 mm or more): 29
Wet days (1.0 mm or more): 23
Snow
Days with snow or sleet falling: 1
Days more than 50% cover at 0900: 0
Deepest at 0900: 0
Sunshine
Total sunshine: 26.5 hours (68% of average)
Sunniest day: 5.4 hours (23rd)
Days with no sun: 16
Other phenomena
Days with thunder heard: 0
Days with hail: 0
Days with fog at 0900: 2
Wind
Mean wind speed: 9.9 mph
Maximum gust: 53 mph (30th)
Days with gale: 0
Remarks
An exceptionally mild month with most temperature statistics being new December record highs since I started recording here in 2009. The sunshine total for the month was the lowest that I have recorded for December.
The perception of it being a very wet month is not supported by the total fall which was only a little above the average. The Decembers of 2011, 2012 and 2014 all had higher rainfall totals. There were a lot of days in December 2015 when it rained for long periods during daylight hours. This is probably why it seemed to be a very wet month.