December 2020 was cooler than average (4.48°C versus an average of 4.85), wetter than average (93.40 mm versus an average total of 51.56) and calmer than average (a wind run of 2657 miles versus an average of 3353).
Temperatures in December were almost average, despite a cold snap with snow towards the end of the month. The highest temperature was 12.2°C recorded at 16:17 on the 18th. The lowest temperature was -3.7°C recorded at 04:18 on the last day, one of six sub-sero temperatures in the month. This was the lowest temperature here since -4.4°C was recorded on February 3rd 2019. The average temperature in the month was 10.2°C, 0.1°C below the December record. The average daily high temperature was 6.9°C and the average daily low temperature was 2.1°C. The warmest day was the 18th with an average temperature of 11.2°C and the coldest day was the 31st with an average temperature of -1.2°C.
The average wind chill in the month was 3.4°C with the average dew point being also 3.4°C. The high dew point was 11.2°C recorded at 16:03 on the 18th. There were 2.97 hours of sunshine, 0.5 hours below the December average. The sunniest day was the 6th with 3.15 hours, almost half of the December average of 5.7 hours. The sunniest day was the 1st with 1.57 hours.
Rainfall in the month totalled 93.4 millimetres, 38.4 millimetres above the December average, and a high for the month. Rainfall was recorded on 28 days with 17.0 millimetres of snow recorded, 15.0 millimetres on the 29th. This was the first snowfall since February 10th 2019. The yearly rainfall total iwas 599.0 millimetres, 105% of the normal for the year. The wettest day was the 23rd with 17.0 millimetres of rain being recorded. The highest rain rate was 24.0 millimetres per hour, recorded at 00:19 on the 18th.
Wind speeds were below average, with the highest wind gust speed of 32 mph being recorded at 22:39 on the 26th. The maximum wind speed was 16 mph at 00:17 on the 27th. The wind run was 2655.4 miles, well below the December avreage of 3744 miles.. The average gust speed in the month was 5.4 mph, and the average wind speed was 3.61 mph. The predominant direction was south westerly (213°).
The highest barometric pressure of 1031.5 millibars was at 09:39 on the 25th. The lowest pressure was 968.3 millibars recorded at 03:33 on the 28th], the lowest pressure since 964.9 millibars was recorded at 00:15 on February 15th 2014, and the second lowest ever here. The average pressure in the month was 1000.1 millibars. The highest humidity was 100% and the monthly average humidity was 93%. The lowest humidity was 72% at 14:19 on the 1st.
The maximum high solar radiation recorded at 11:52 on the 19th was 343 w/m². The average solar radiation for the month was 18 w/m². The U.V. Index was 0.0 for the month.