After a mild, wet end to 2020 the new year began with a frost, down to -2.8°C which was to prove the coldest night of January. There was also a light sprinkling of snow. It did not develop but remained cloudy. The first ten days continued similarly with light winds between NNW and NNE. Daytime temperatures ranged between 4.9°C on 4th to 0.8°C on 7th the coldest day of the month. Nights were between 1.7°C & -2.8°C and there were air frosts on five nights between 6th & 10th. On 6th a ridge of high pressure brought sunny periods followed by frost and fog on 7th-9th, only clearing slightly during the day.
The wind swung round to WSW on 10th, the temperature rose to 8.6°C on 11th, with 4.0mm rain overnight of 11th/12th, the first significant fall of the month. Unsettled, milder conditions continued until 20th, with rain recorded on all days although sometimes only a few millimetres or less. Storm Christoph brought 10.5mm of rain on 20th. The temperature ranged between 3. 5°C on 15th to 11.1°C on 19th. Corresponding night minima were between 8.8°C on 19th and 0.6°C on 15th.
The barometer began to fall on 23rd and a colder, frosty spell with lighter winds lasted until 26th when it went down to -2.4°C. There was 3cm of snow on 24th.
The last five days brought warmer, windier weather with the temperature rising to 12.1°C on 28th, the warmest day of the month. The nights of 28th & 29th did not fall below 8.6°C and 7.8°C respectively. These last days were particularly wet and with 19.4mm on 26th/27th and 15.1mm on 28th/29th which brought the total for the month to 96.2mm, 145% of average. This makes it the wettest January since 2014 and the second wettest since 1995.
In summary, January was a wet month with 22 days recording rain, generally cloudy and dark with mainly light winds but little sunshine. There were no extremes of temperature but with nine slight air frosts and an average temperature 0.43°C below my long-term average.
25 year Rainfall averages are from 1992-2016
30 year Temperature averages are from 1981-2010
30 year temperature averages for Steventon are from 1981-2010
Oxford rainfall averages are from 1992-2016
Summary data from Mike Wilkins, January 2019.