Summer is getting longer fast

That’s what they say Environmental Research Letters Canadian researchers in the scientific journal. They studied the temperature records from 1961 to 2023 and looked at the thermal summer.

In Finland, thermal summer is defined as a period during which the daily average temperature remains above ten degrees. In different climatic conditions, the limit value has been agreed to be different.

It turned out that the thermal summer is now on average 30 days longer than in the 1960s. Summer is getting longer at both ends, that is, spring ends earlier and autumn starts later.

In addition lengthening accelerates. It has previously been reported that from the middle of the last century to the beginning of the 2010s, summer lengthened by an average of four days per decade.

Now it turned out that in the period 1990–2023 the rate of lengthening has been 5–7 days per decade. The summer of 2023 was about 20 days longer than that of 1990.

Idea more balmy summer days might sound nice, if the summers weren’t also getting hotter.

After 1990, the summer heat total in the land areas of the northern hemisphere has grown more than three times as fast per decade as in the previous three-decade period.

When there is enough heat for a long time, the drought periods also become longer. Wildfires are becoming more common.

Spring at the end and beginning of autumn, the temperature change is becoming more sudden on average. It leaves less time for organisms to adapt.

In the spring, the lake ice can melt faster than before, as can the ice. It can make flooding worse.

The first hot season of the summer can strike so early that it is difficult for both nature and people to adapt when they are still used to the coolness.