Saturday was another day when the northeasterly air flow limited the rise in temperature with a flow of cool air that resulted in a maximum of 9.7C at 14.27 being 1.0C below the early March average. It was almost wall to wall sunshine although the very thin, high could meant the peak solar radiation was the lowest for three days. During the evening the thermometer slowly fell away to reach freezing point (-0.1C) at 20.51, hovered around -1.2C for a couple of hours then continued to drop reaching a minimum of -4.6C at 07.02 on Sunday being a significant 6.5C below my long-term average.
The UV level peaked at 2.3, the highest since 18th October 2024 and at the top end of ‘Low’. Not surprisingly, the equivalent loss of rainfall through evaporation from ground sources and plant life increased again to 1.47mm
Sunday after dawn revealed another clear sky and sunshine as soon as it rose above the horizon, so another fine day ahead. The significant change is in the direction of the wind that has veered into the southeast, a sightly warmer direction, signalling a small but significant change in our weather ahead as the daytime temperatures will begin to ease upwards. The breeze will continue very light under the dome of high pressure that at 08.00 registered 1035.5mb, the highest pressure since 6th February.
The anticyclone is still centred over the UK. The forecast synoptic charts indicate that the high pressure will dominate our weather well into the new week with much fine weather ahead and the temperature easing upwards with still light winds.
Although we are enjoying many hours of sunshine the colder nights have seen the temperature of the soil at a depth of 5cm slowly drop away, not good news for early gardeners, with a temperature of 0.6C at 08.00.
February 2025 Review
The month began with three mild days that produced above average maxima with the wind from the south, peaking at 10.7C on the 3rd, which was 2.4C above the average.
It all changed when a large area of high pressure developed over the country extending east across to the far Continent. The barometric pressure on the 6th was logged at 1044.7mb, an unusually high pressure. That was the highest pressure since 5th February 2023. The anticyclonic dome brought cold, moist air on a persistent northeasterly that depressed temperatures by day, the maximum of just 3.1C on the 10th was the coldest day 10th January. These were depressing days.
Nighttime minima were mostly above average due to the continuous thick cloud that acted as a duvet restricting the loss of any warmth into the atmosphere.
On the 9th a very large area of low pressure in the eastern Atlantic pushed a very wide rain band across the country, the most significant precipitation for a week, with a fall of 16.2mm recorded.
The diurnal range of temperature, the difference between night and day extremes, was unusually small on the 10th with 3.1C by day dropping to just 2.3C overnight, thus a difference of just 0.8C.
The high pressure persisted throughout the second week with very cool, moist air on a modest northeasterly breeze. There was no sunshine to produce any warmth by day, just gloomy weather, although the wind was light with minimal wind chill.
The first indication of a change from the cold, gloomy days was sunshine on the 17th that saw the UV light sufficient to trigger the UV sensor continuously between 10.00 and 16.00 with the greatest strength since 31st October, with a reading of 1.3, even so it was still in the ‘Low’ category.
After a ten day battle the high pressure gave way to the depression on the 19th that brought a significant change in our weather. The cold, gloomy days with calm conditions gave way to more unsettled conditions with welcome higher temperatures but periods of rain. The barometric pressure dropped to its lowest all month with a low of 1004.4mb on the 21st.
The stream of warm air from around the Azores region saw maximum temperatures rise again to double digit maxima with 13.4C logged on the 21st being 4.1C above my long-term average.
The wettest day of the month occurred on the 23rd when several hours of continuous rain, heavy at times, produced a daily total of 18.0mm. In the first of two short but sharp showers on the 24th small hail (classified as less than 5mm in diameter) were observed that in the space of ten minutes saw the temperature drop over 3C.
An anticyclone developed in the eastern Atlantic throwing a ridge across the country on the 27th producing a significant change in our local weather with fine dry days although nighttime air frosts occurred under clear skies as it’s centre settled over the country, just to the north of Marlborough.
The high pressure built on the 28th that saw the highest UV all month with a reading of 2.1, which was at the top end of ‘Low’, also the highest since 18th October 2024. Because of the many hours of sunshine and the light breeze that was less humid, the equivalent loss of rainfall due to evaporation from ground sources and plant life was 1.35mm.
The total rainfall for the month was 76.2mm being 112% of the 40-year average or plus 8.2mm. There were three days when fog was observed in the morning and one day when small hail was observed.