Jaw-dropping heat: How likely is 40C in the British Isles?

Some frightening temperatures remain on the cards heading into the weekend and early next week, but how likely really is it?

At first, it was just one weather model, the GFS, pushing for seemingly absurd temperatures into the 40s Celsius, but as the days have gone on, this weather model is no longer standing alone.

Other models have now begun lining up with similar figures, suggesting that we could potentially shatter the UK’s all-time temperature record of 38.7C.

The all-time temperature record of 38.7C was observed in Cambridge in July 2019. Out of the last 100 years of records, twelve of those years have seen temperatures rise above 35C in the British Isles, four of which have occurred since 2015.

Whilst it once seemed almost impossible to reach 40C in the British Isles, it also seemed similarly unlikely to reach 50C in northwest Canada, or 30C in arctic Russia. However both occurred in June 2021 and June 2022 respectively.

In the British Isles, conditions to achieve these kinds of heights must be just right, and it all relies on the track of a plume of exceptionally hot air being transported from the south, accompanied by high pressure.

Once this forecast period comes into the short-range, high-resolution models, confidence in these model outputs can build.

A model output isn’t a forecast, but it does show a possibility, however small. So, whether we will see 40C next week or not is still uncertain for now, but extremely alarming that it is no longer unrealistic.

Keep an eye on our TemperatureRadar to check out the temperatures three days ahead.