October heatwave expected in parts of Europe after countries record hottest ever September

Countries across Europe experienced their hottest September on record with unseasonably warm weather expected to continue into October.

Austria, Belgium, France, Germany, Poland, Switzerland and the UK all saw record-high temperatures last month, upwards of 3.6°C above seasonal norms.

The EU’s Copernicus Climate Change Service (C3s) expects 2023 to be the hottest year humanity has ever experienced.

How hot was Europe in September?

French weather service Meteo-France recorded an average of 21.5°C, marking the hottest September since measurements began in 1900. This is more than 3.6°C above the 1991-2020 normal and above this year’s July and August average of 21.1°C.

September heatwave alerts were issued in the country for the first time, with the centre-west département of Vienne recording 38.8°C earlier in the month - the country’s highest ever September temperature.

Germany recorded an average of 17.2°C in September - almost 4°C above the 1961-1990 average.

“The extraordinary temperatures in this year's record September in Germany are further evidence that we are in the midst of climate change," said Tobias Fuchs, head of the climate and environment division at the German Weather Service (DWD).

In Poland, temperatures were 3.6°C above average and the hottest for September since record-keeping began over a century ago.

The UK saw average highs of 22°C, a significant increase on the previous record of 20.9°C set in 1895.

Will high temperatures continue in October?

High temperatures are expected to continue this month in parts of Europe. The UK experienced a heatwave over the weekend - on Sunday London recorded its hottest temperature for October in the last five years.

A heat dome developed over Western Europe last week, with temperatures rising as high as 37°C in Portugal and Spain and 35°C in southwest France.

Spanish weather agency AEMET says temperatures are set to soar 10°C above normal for this time of the year, bringing an increased risk of fire in some places.

Several places in Croatia recorded record October temperatures over the weekend, and the heatwave is forecast to continue this week.

Heat-trapping greenhouse gases and the El Niño weather event have led temperatures to hit record highs this year - a trend that’s set to continue over the next five years, according to the World Meteorological Organization (WMO).

The phenomenon may also bring cooler weather, however. In the UK, the temperatures are set to drop this week with rain arriving from the north.

Heavy rains in Scotland and northern England caused severe flooding over the weekend and a yellow weather warning is in force for parts of western Scotland on Tuesday.

Weather experts are warning El Niño could also bring plummeting temperatures and heavy snow to the UK in December.

The COP28 summit next month will see world leaders debate how to curb climate change and stick to Paris Agreement goals. The phasing down of fossil fuels to reduce planet-heating greenhouse gas emissions will be a key topic.