HEADLINE writers love superlatives such as ‘hottest ever but they haven’t been able to use that one in August since 2003 – until just recently. Nowadays August is usually characterised by moderate daytime heat and very warm nights, as was the case for most of the month just ended.

The first three days offered sunshine enough to raise temperatures above the seasonal average, August 2, having a maximum of 25.7C (78F) in Wellington. August 4 marked the start of an unsettled spell, as the upper atmosphere jet stream at last began to blow purposefully across the Atlantic, bringing rain-bearing frontal systems with it. August 6 was breezy with heavy showers in Wellington during the afternoon, while the next day was dry there but with downpours seen over the Brendons.

Heavy rain was forecast for August 8, and this arrived in no uncertain fashion during the evening, continuing on and off through the night, which was nonetheless very warm with a minimum in Wellington of 16.6C (62F). The following day was blustery with further heavy rain arriving later, giving a combined total of more than 30mm (1.2in) in as many hours, almost half the month’s eventual total. For a few days after this it remained unsettled and showery, but was still warm with fair amounts of sunshine, and we missed the thunderstorm that struck the Blackdowns on August 11.

August 15 was warm and sunny, but we were warned of another deep Atlantic depression on its way. Next day there was rain or drizzle from the start with a strong, gusty south-west wind, which limited the maximum temperature to just 17C (63F). Skies then cleared, to make Saturday, August 17 the sunniest day in the month up until then. As things turned out, the next nine days would be mostly sunny, with air pressure on the rise. Daytime temperatures were above normal as the anti-cyclone edged across Britain into the near continent. Once there, it began to draw up very warm air from the south, with a maximum of 24.5C (76F) in Wellington on August 23.

Forecasters gave notice of a heat-wave arriving for the Bank Holiday weekend. They were right. After a cool start on Saturday, August 24, unbroken sunshine boosted the mercury to 28C (82F) in our area. Only the development of thundery cloud the next day prevented that from being even warmer, while cloudy starts on August 26 and 27 didn’t stop them from also becoming hot and humid by afternoon.

Placing the recent headlines in context, we may have enjoyed our hottest-ever late August Bank Holiday, but higher temperatures have occurred later in the year. Worthy of note is 1961, when readings in excess of 30C (86F) were reported widely in southern England – including in our area – on September 2, our hottest September day in living memory.

That scenario was not repeatable this year, as August ended with westerly winds bringing much more changeable conditions. It was nevertheless a good month overall, much sunnier than normal, with a mean temperature of 17.4C (63.3F), and the fifth August in the present decade to be significantly warmer than the long-term average. In spite of the earlier wet spell, the total rainfall was only fractionally above average at 68mm (2.7in).

Simon Ratsey

WWN weather correspondent