UK faces elevated heatwave risk in September as drought persists

Britain is bracing for what could be an unusually warm autumn. While rain finally arrived this week after nearly two months of dry weather, bringing temperatures down several degrees, meteorologists are already watching for signs of another heatwave—potentially the sixth of the year—taking shape in September.

The summer of 2026 has been exceptional by any measure. The Met Office is tracking it as likely the hottest on record, a prediction made back in June when forecasters flagged the combination of natural weather patterns and human-driven climate change as a recipe for sustained heat. Even with this week's cooler spell, the last two weeks of August would need to be significantly colder than normal to prevent the year from breaking the record set just twelve months ago. The pattern has held: heatwave after heatwave, each one a punctuation mark in an unusually hot season.

Now attention is turning to what comes next. Long-range computer models suggest that high pressure could settle in south of the UK as September begins, the kind of atmospheric setup that typically brings dry, sunny conditions and can draw warm air up from continental Europe. The Met Office's seasonal forecast for autumn—September through November—indicates a higher-than-normal chance of warm spells, with particular emphasis on heatwave risk during the first half of September. But forecasters are cautious about specifics. Two weeks out, they can only say the risk exists; when or whether it will materialize remains uncertain.

What makes September potentially dangerous is the ground beneath our feet and the water around us. July was the driest month on record across England and Wales, with more than two-thirds of England and all of Wales now officially in drought. Dry soil acts as an accelerant for heat. When moisture is absent, the sun's energy doesn't get consumed by evaporation; instead it goes directly into warming the air, causing temperatures to spike faster and higher than they would over wetter ground. The rain arriving this week will provide some relief but not enough to reverse the drought. The Environment Agency has warned that weeks of above-average rainfall would be needed to genuinely alleviate the situation.

The sea adds another layer of concern. Waters around England and Wales are running 3 degrees Celsius above their seasonal average, an unusual warmth that radiates back onto the land and can sustain higher temperatures even when the sun weakens. Together—dry soil, warm seas, and the possibility of high pressure overhead—these factors create what meteorologists call loaded dice: conditions that tilt the odds toward heat.

The long-range outlook also suggests that autumn itself will likely be drier than average, meaning the drought that has defined summer may simply persist into fall. For now, the immediate forecast brings cooler weather and rain. But September waits, and with it, the possibility of heat returning before the year finally turns toward winter.