Once again the maximum temperature on Monday was recorded around midday after the early morning sun got to work before cloud cover built up. A peak of 20.4C was logged at 12.44 being just above the early September average at +1.4C. There were two very heavy showers in the afternoon, the first beginning at 13.30 the second just after 14.15 that produced a total of 8.2mm, being intense for a very short period. The past night was also mild with a low of 10.0C logged at 06.04 being 1.3C above average.
Tuesday began with very weak sunshine shining through very thin cloud on the eastern horizon that soon became obscured as thicker cloud began to drift over well before 08.00. The wind fell out just after 04.00 and the anemometer was stationary until just before 08.30 when there was a hint of movement. Shower activity is imminent after around 08.30. As the depression has been relocating it has changed the wind direction from southwest recently, to southeast today, before beginning to veer back into the southwest later today.
The secondary low pressure that I mentioned yesterday has moved eastwards and by midday is forecast to be over the Dorset region. Associated with it is another weather front that on the radar showed pushing along a large area of scattered heavy shower activity. This depression will, by tomorrow, edge northwards over the country, however, developing on its southern flank will be a very disturbed area of heavy rain and very strong winds likely arriving before dawn on Wednesday.
August 2025 Review
The new month continued with the modest strength north-westerly, travelling around northern periphery of the ridge of high pressure with variable cloud. The 3rd brought a very warm day as the wind had backed into the west with a maximum of 24.4C.
In winter we often hear about wind chill when the temperature is low and there is a strong wind blowing that makes it feel colder outside than indicated on the thermometer, referred to as the THW factor using data of temperature, humidity and wind strength. The opposite has occurred over the past few months when we have had very high temperatures, referred to as the Heat Index (THSW) that uses the additional data of solar strength that makes it feel hotter outside than indicated on a thermometer.
Taking the data from the 2nd as an example, although the maximum on the thermometer read 22.3C at its peak at 14.30 outside it was computed to feel more like 28.3C. That was one hour after 13.30, peak time under BST, when the solar read 849W/m2.
The 4th was notable for the arrival of the fifth Named Storm of the season being Storm Floris that paid a one-day visit, predominantly to Scotland. However, being on the periphery we only experienced gusty winds up 26 mph and modest rainfall in the afternoon of 1.4mm. The centre pf the deep depression had a minimum pressure of 976mb whilst at 08.00 locally it was 10167mb. The considerable pressure differential cased the storm force winds in the north but no gales over Southern England, just very windy.
Temperatures began to climb again from the 10th under a large area of high pressure that heralded the arrival of the fourth Heatwave this year. The peak temperature was logged on the 12th when the thermometer reached 32.8C being 10.7C above my long-term average.
There followed a quieter period in the third week with maxima below average due to a brisk breeze coming around the north of the high pressure then arriving from the northeast.
The Bank Holiday once again saw the temperature very briefly soar again to reach 27.5C, some 5.4C above average.
A significant change in the weather pattern was heralded on the 26th as the remains of ex-hurricane Erin was absorbed into a deep depression in the North Atlantic. This resulted in the wind veering into the southwest with an Atlantic influence on our weather and the first precipitation after fourteen consecutive dry days. The rain spots at 06.30 followed by very brief, light drizzle amounted to 0.2mm.
The cooler and more moist air also meant a drop in temperatures that for the last few days in the month were below the average.
There was substantial and welcome rainfall on the 28th that began to quench the thirst of parched ground, much to the relief of gardeners. It was mainly intermittent rain with the longest period in the evening that eventually totalled 16.8mm being the wettest day since 23rd February.
There were 25 dry days in August equalling those recorded in April. The remaining days, when rain did fall, produced a total of 31.1mm, which was 47% of my 41-year record or minus 34.4mm. The wettest day was on the 28th with 16.8mm. Set against this limited rainfall was the loss of equivalent rainfall through evaporation from ground sources and plant life that totalled 94.0mm.
It was another very warm month with the average temperature 2.1C above almost entirely due to the very hot days as there were fourteen days when the overnight minimum was below average. The hottest day (12th) reached 32.8C when the coolest day (20th) only reached 18.3C, which was 3.9C below average.
The warmest night was recorded on the 13th with a minimum of 16.4C whilst a very cool night was logged in the early hours of the 22nd with a low of just 4.5C, being a significant 6.5C below my long-term average.
Summer 2025.
The three metrological months of Summer, being June, July and August, produced a mean temperature of 18.29C, being 1.8C above my long-term average.
The rainfall for summer totalled 116.2mm, which was 67mm below my 41-year average.
