Now in June, climate scientists are starting to gain some perspective on how warm May actually was.

And the results are exceptional. In Stockholm, the average temperature was 16.1 degrees – something that statistically only happens three times in a million years.

– It is not unusual to have a couple of days that are summer-warm, but now we had almost a whole month that was this warm. May felt more like July, says Gustav Strandberg, climate researcher at SMHI.

The month of May was warmer than normal almost throughout the country and SMHI's measuring stations have registered many new records. Some are more than 2 degrees higher than the previous monthly average temperature. It was only in the southernmost south and northernmost north that no records were broken.

”A couple in a million”
In Stockholm, there are temperature records from 1756, which is a boon for climate scientists who want as much data as possible. The average temperature there in May was 2.2 degrees higher than the previous record from 1993 of 13.9 degrees.

"We don't see the likelihood of such a warm May again at first," says Gustav Strandberg.

– It's very small. It's one or a couple in a million.

Otherwise, Norrköping had an average temperature of 16.1 degrees, which is the largest increase of 2.5 degrees compared to 1992. However, Gothenburg had the highest average temperature in May, recording 17.6 degrees, but the measurement series there is about a hundred years shorter than Stockholm's.

New climate
At the same time, the probability of high temperatures will change in the future.

– We live in a different climate today that is warmer, so the probability of extremes increases with warming. But we cannot do such an analysis for the future. But a May like the one we had this year was very extreme and it will always be extreme, says Gustav Strandberg.

TT: How long can the heat record last?

– It's very difficult to guess. But several hundred years is not impossible at all, or even more. If it only happens three times in a million years, it could be thousands of years.

Source: TT