After a refreshing end to August, meteorological forecasts suggest a significant increase in temperatures across France during the first week of September 2026. While the possibility of a new heatwave is being discussed, particularly in Paris and the Île-de-France region, the exact intensity and duration remain uncertain.
Significant Rise in Temperatures Expected
The contrast in weather could be stark. A cooler air mass swept across France after severe thunderstorms on Thursday, August 27th. This led to temperatures struggling to exceed 20-21°C in Paris on Saturday, August 29th.
However, this cooler interlude is expected to be brief. Latest European ECMWF model simulations indicate a powerful surge of hot air from the Iberian Peninsula starting Thursday, September 3rd, potentially peaking on Friday, September 4th, and Saturday, September 5th.
In the most extreme scenarios, temperatures could exceed 35°C in the Southwest and even locally approach 40°C. However, with nearly a week until this period, these values are not yet confirmed, as different scenarios still show significant variations. Nevertheless, the signal for a rise in temperatures is becoming increasingly clear.
What to Expect in Paris and Île-de-France?
Paris and the Île-de-France region are not expected to be entirely spared from this change in weather. However, the projected temperatures are, for now, much less dramatic than in the south of France.
ECMWF projections suggest temperatures 2 to 4°C above seasonal norms across parts of the northern half of the country. In Paris, various forecasts have not yet converged sufficiently to provide a precise value for September 4th and 5th. Some scenarios predict temperatures close to or slightly above 30°C, while others remain below this threshold.
In other words, a return to summer-like conditions appears credible, but not exceptionally high temperatures at this stage. Furthermore, by early September, nights are already significantly longer than in the middle of summer. This could allow temperatures to drop sufficiently to avoid meeting the criteria for a heatwave.
The duration of this warm spell also remains highly uncertain. Météo-Paris on Saturday suggested a rise in heat but estimated it could be relatively short-lived.
Forecasts Still Evolving
Caution is therefore essential. At a six or seven-day forecast horizon, models can indicate a trend but cannot yet precisely predict the temperatures that will be recorded in Paris. While the scenario of a new hot spell is to be monitored around September 4th, 5th, and 6th, the prospect of a genuine heatwave still requires confirmation.
Source: https://actu.fr/meteo/crainte-d-une-nouvelle-canicule-en-france-a-quoi-faut-il-s-attendre-a-paris-et-en-ile-de-france_64722965.html
