Europe will once again be hit by an abnormal heatwave with temperatures reaching up to +40°C in late September

 

The cause will be an influx of hot air from North Africa:

 A massive Heat Dome is making a dramatic return across Europe as September draws to a close, setting the stage for an unseasonably warm spell that will stretch into early October.

 A powerful upper-level ridge building north from the Mediterranean and North Africa is driving a warm plume northward.

Temperatures could be 10–14°C above the seasonal average.

The most intense heat is expected in Spain and Portugal, reaching +35…+38°C, with localized highs of around +40°C.

Temperatures of up to +35°C are forecast for France.

 Unusually intense for early October, values will climb significantly above normal norms from France into Denmark and the Baltic.