The freshness makes a noticed return and the nights will become very cool at the end of the week. Climatologically speaking, the last decade of August often marks a remarkable decline of summer in France.
Refreshment under a northern flow
A cold drop is currently circulating above France and brings unstable weather with a clear decline temperatures this Wednesday, August 20, 2025. At the rear of this depressional anomaly, the flow will switch to the northern sector and will advete an increasingly fresh air mass. As the animation below shows, this fresh air will come from Scandinavia and from the Norway sea. We must therefore expect temperatures passing under normal with nights becoming increasingly cool.
Air mass at 850 hpa (around 1500m) from Wednesday 20 to Saturday 23 August 2025 – wxcharts.com
In the coming days, maximum temperatures will often be slightly below seasonal normal. This Wednesday, August 20, 2025, only the Mediterranean regions will be entitled to values greater than 20 ° C. This will also be valid Thursday August 21 with only 18 to 22 ° C on Auvergne-Rhône-Alpes. Diurnal temperatures will rise timidly at the end of the week, especially in the southern regions, thanks to a sun with the advantage.
Maximum temperatures scheduled from Wednesday 20 to Saturday 23 August 2025 – Cities weather
In addition to diurnal temperatures significantly lower than in the last two weeks, we will also witness an accentuation of night freshness. It will especially occur from the morning of Friday August 22, 2025, thanks to a sky emerging during the nights. Thus, the mornings on Friday and Saturday will be the coolest with minimum temperatures frequently lower than 10 ° C in the northern, center and east regions. Values of 5 ° C are possible towards the Ardennes or the Massif Central. They will start up slightly from Sunday August 24, 2025.
Minimum temperatures modeled from Thursday 21 to Sunday 24 August 2025 – wxcharts.com
After two weeks excessively hot and with buildings that are still hot in many regions, this freshness will be a boon and will allow you to definitively get rid of the heat that has invaded the places of life.
Summer often declines around August 15-20
It is often said that after August 15, summer bows out. Even if this is not quite correct, it should still be mentioned that mid-August generally marks a turning point. Indeed, climatology shows that average temperatures in France reach their peak around the end-July. They hardly evolve in the first half of August and then begin a fairly clear drop from mid-August, which accelerates in the last decade of the month. It is therefore not just an impression: summer has the habit of declining around these dates.
Evolution of average temperatures in France throughout the year – infoclimat.fr
However, this does not mean that summer is over and that the heat will not come back. The recent years have shown us that hot weather can still be largely present in September, or even overflow until early October.
Author: Alexandre Slowik