December 2017

It was a cold start to December, with a ground frost, but the daytime maxima gradually rose from 4.9°C on 1st to 12.7°C on 7th. Nights ranged from 0.8°C-7.4°C. There was little sun and there were showers on 2nd & 6th.

A rapid fall in the barometer on the night of 8th/9th brought the temperature down and rain from the south east, turning to snow. The snow continued until 3pm adding up to a depth of about 75mm. The total rain equivalent was 23.3mm. The temperature only reached 1.5°C on 10th and 1.4°C on 11th, the coldest day of the month. This was followed on 12th by the coldest night, 4.1°C.

11.2mm more rain followed on 12th/13th. The following nine days were more settled and dry with light to moderate NW winds and some sunny spells. Daytime temperatures steadily increased to a maximum of 11.3°C on 21st and night minima ranged from -1.5°C on 19th to 8.8°C on 21st. Just 3mm rain fell in this period, on 19th/20th.

I was away from 24th-27th but the weather continued unsettled with fresh W-SW winds. There was 32mm rain over the period.

The remaining four days steadily warmed up, reaching 12.9°C on the last day of the year, the maximum for the month. Although there were night frosts on 28th & 29th overnight rain kept the minimum up to 4.3°C on 30th and 6.0°C on 31st. Average temperature was just about equal to my 30 year average and that for the year was just under 1°C above.

Total rainfall for the month was 75.4mm, 14.1% above my 24 year average. It followed two dry months. The year's total was 617.2mm, 90.5% of average.

Overall, December was a mixed, unsettled month with something of everything, but not particularly extreme.

Mike Wilkins