Cool August pulls down Iceland’s summer average

August was relatively cold and wet across Iceland, especially in the north and west, lowering the country’s average summer temperature, mbl.is reports.

Average summer temperatures nationwide reached 10.0°C, which was 0.3°C above the 1991–2020 average and close to the average for the current century. June and July were warm, while August was cold.

Summer was relatively warmest in eastern Iceland and cooler in the west. July was unusually warm and dry in the east, where it ended in many places among the warmest and driest Julys on record. By contrast, the southwest and west were considerably wetter and colder.

In Reykjavík, periods of rain characterised much of the summer, although sunny spells brought relief to residents and visitors.

September could still affect the summer average

The World Meteorological Organization defines June through August as summer in the Northern Hemisphere. The Icelandic Met Office, however, considers September a summer month, meteorologist Trausti Jónsson notes in his mbl.is blog, Hungurdiskar.

“The Met Office summer” is therefore not over yet, Jónsson writes. September has greater temperature variability than the other summer months, and if it stands out from them, it can have a significant effect on the average temperature for the summer as a whole.

Jónsson says the summers of the 1960s and 1970s remain prominent in his memories from when he was a teenager and in his thirties. Temperatures have risen by more than 1.2°C in the 50 to 60 years since then.

“Is it any wonder that he feels all summers are now warmer and better than before, even the poorer ones?” Jónsson writes.

Cold summers have been slow to appear in recent years, with 2015 perhaps the main candidate, he says.

“Global warming will not eliminate cold summers any time soon, and no one should be surprised if such a summer suddenly appears. But no global summer has yet become ‘off the charts’ in terms of warmth. We are still waiting for a 12-degree summer. It could come,” Jónsson writes.

Temperatures varied across the country

In Reykjavík, the average temperature for the three summer months was 10.7°C, or 0.2°C below the 1991–2020 average. It ranked 46th or 47th among 156 years of records.

Akureyri recorded an average of 11.0°C, which was 0.5°C above the 1991–2020 average. The summer ranked 25th or 26th among 146 years of records there.

The average summer temperature in Stykkishólmur was 10.1°C, exactly matching the 1991–2020 average. In Egilsstaðir, the average was 10.8°C, or 0.8°C above average, making it the 11th-warmest summer in 72 years of records.

At Dalatangi, the average temperature for the three summer months was 9.3°C, or 1.1°C above average. It was the second-warmest summer in 87 years of records there, surpassed only by the summer of 2021. At Stórhöfði, the average was 9.9°C, or 0.1°C above average.

Reykjavík recorded 539.9 hours of sunshine during the three months, just above the 1991–2020 average by 2.4 hours. The summer was sunny in Akureyri, where 564.9 hours of sunshine were recorded, 84.5 hours above the 1991–2020 average.