February began with a mild, moist airstream brought from mid-Atlantic on a westerly breeze around the large anticyclone as it edged further south. The daytime maximum on the 3rd was 10.6C being 2.6C above the 39-year average.
However, an extensive and intense high-pressure system developed, reaching from mid-Atlantic to Russia, that began to influence our weather from the 5th. Under clear skies the thermometer fell steadily during the hours of darkness to produce hard air frosts on three nights with a low of -5.8C in the early hours of the 8th.
With crystal clear skies the full moon could be seen shing brightly and is often referred to as a ‘snow moon’. According to NASA, the second full moon of the year gets its name from the tribes in Northeast America who named it because of the heavy snowfall the season often gets. It is also referred to as the ‘hunger moon’, due to scarcity of food and hard hunting conditions.
The extensive high pressure formed a block to weather fronts from the Atlantic until the 15th, when there was a distinct change in our weather.
After nineteen continuous dry days a weather front arrived in the evening of the 15th with light rain from brief showers and drizzle that amounted to just 1.2mm. This was the wettest day for a month, since 4.0mm was recorded on January 15th, previously only 0.1mm on the 26th of January.
After many days of calm or minimal air movement, often maximum gusts in single figures, the wind changed into the southwest and then south with moist, warm air from the Atlantic. A maximum of 13.7C on the 15th made it the warmest day since 14th November.
A further brief period of mild, damp weather arrived on the 21st with the wettest day of the month on the 22nd producing 5.6mm. However, this did little to change what had been a very dry month, taking the total to 12.1mm by the 24 th. This amount was just 18% of the 39-year average or 55mm below.
A new anticyclone settled to the north of Scotland from the 25th bringing another significant change to our weather. The winds revolving clockwise around the high pressure, as they do, arrived over the UK from the northeast. This air stream is from a cool direction so both maximum and minimum were subsequently below average.
The coldest day of the month occurred on the 23rd when the thermometer struggled to reach 6.5C, which was 1.5C below the 39-year average.
The brisk wind, gusting to 25mph, combined with the lower temperatures, produced a wind chill that meant outside it often felt up to 3C below that registering on a thermometer.
During the hours of sunshine at the end of the month the UV level rose to a reading of 1.9, which is still classed as ‘Low’ but the highest since October.
The mean temperature for February was 1.0C above the 39-year average. However, this masks the fact that the mean minimum was almost exactly average whereas the mean maximum was 2.0C above the average, principally due to the warm, first half of the month.
It was the driest February for 30 years with just 12.2mm of rainfall. The two previous drier months were in 1993 with 10.9mm and February 1986 with only 9.9mm. There were 22 dry days when the 39-year average is 13.
The minimal rainfall is only half of the story as the equivalent of 16.4mm of rainfall was lost through evaporation from ground sources and plant life, exceeding rainfall by 4mm.
An air frost was recorded on 11 mornings, average over 39 years, with the coldest in the early hours of the 8th with -5.8C.
The persistent high pressures systems meant that the average barometric pressure of 1029.4mb was 15mb above the long-term average.
The average temperature for the past three months was 0.3C below the average making it the coldest winter since 2017. With a mean of 4.05C it was well above the coldest winter of 2009 (2.03) but well below the very warm winter of 2015 (6.4C).
The three-monthly rainfall total was 248mm. The very wet months of December and January offset the very dry February. The 39-year average is 249mm. The extremes were in 1991 with just 94mm and 2013 with 528mm.
By February, the UK would normally have had around three storms given names by the Met Office. But so far this autumn and winter, there has been only one. That was Storm Otto, named by the Danish Meteorological Institute, as it hit them much harder than for most of the UK, although Scotland suffered greatly. Weather patterns have been calmer across the Atlantic and towards northwest Europe.
There are several factors at play – and the forces behind this year’s lack of storms were instrumental in December’s cold snap. In previous years, the first named storm has taken place in December. By the end of January three storms would have formed, bringing impacts to the UK.
Windstorms in the UK are usually caused by little wobbles in an active jet stream (a corridor of strong winds around 30-40,000ft up in our atmosphere) over the Atlantic directed towards northwest Europe. Naming storms was started by the Met Office and Ireland’s Met Eireann in 2015, with the idea of being able to communicate the hazards and warnings associated with them.
The UK’s lack of named storms this season is likely to be due to the position of the Polar jet stream, a ribbon of strong winds high in the atmosphere that create and drive weather systems across the Atlantic to northwest Europe.
The busiest autumn/winter season was in 2017/2018, when a total of seven named storms had hit the UK by the start of February.