Monday 29th June
There was a distinct change in the weather on Sunday as two cold weather fronts crossed the area, the first produced light drizzle for about five minutes at 09.10, but insufficient to be measurable. The associated cloud and cooler air behind the fronts meant that the maximum of 23.9C at 14.33, was only 3.1C above average making it the lowest high since the 20th, which brought the recent heatwave to a close that lasted for seven days.
Unfortunately, the Daily Statistics page under the ‘This Month’ tab, did not automatically save yesterday for some unknown reason, not the first time.
There was a hesitant start to Monday due to variable cloud, even so, the thermometer had recovered to 15.1C by 08.00, which made it the coolest start to a new day at that time since the 15th. A depression is closing in on the UK, towards Scotland, that will mean much more cloud today and comfortable temperatures by day and night. The barometric pressure read 1026.7mb at 08.00, and was rising steadily, almost equalling the peak on the 22nd as the heatwave built.
There is going to be a little tussle between the opposing pressure systems over the next few days before it looks likely the Azores high might become a significant feature from next weekend with another possible heatwave arriving. At the moment the BBC weather forecast indicates that Sunday the 5th will see the heatwave threshold of 27C arrive and lasting for the following week, however, the Met Office at the moment suggest a maximum of 24C on the 5th and have no forecast for the following week. There does seem to be a rise in confidence that the week following Sunday 5th will be very hot as the forecast surface charts indicate that the Azores high will build significantly across the country that will result in many hours of sunny, very hot weather.
I have analysed my records to extract the number of days when 30C or above was recorded, which is 3C above the heat threshold for Wiltshire of 27C. Looking at the data since 2011 and subdividing it into five year periods I find a rising trend in the very hot days. From 2011 to 2015 there were just 5 days that reached 30C or above, 2016-2020 there 19 days when 30C or above was recorded whilst the years 2021-2025 produced 30 days with 30C or above. This year we have already endured 10 days at 30C or above and we are only at the beginning of the summer season.
I attach a recent meteorological article on the possibility of another heatwave arriving next week.
The UK is set to be hit with another “heat dome” in mid-July causing more extreme weather across western Europe, experts have said.
The current heatwave, which saw Britain’s highest recorded temperature in June on record, came to an end on Sunday but forecasters are predicting a repeat of similar conditions next month.
According to the European Centre for Medium-Range Weather Forecasts (ECMWF), the Azores High, a semi-permanent high-pressure system situated over the North Atlantic, is expected to become “displaced” and therefore become centred over northern France and southern Britain instead.
As a result, another burst of intense heat is set to be created over Spain and Portugal before moving further north, creating temperatures far higher than average.