Fall weather 2022: are the heat waves likely to continue until October?

Meteorologists are sounding the alarm. France is facing one of the hottest, but above all the driest summers on record. Heat waves, thunderstorms, absolute temperatures… Several inglorious records have been broken in recent months, and the trend is not about to be reversed.

According to AEMET, the Spanish meteorological agency, it would even be the opposite: heat waves could persist throughout the summer but also at the beginning of autumn, until October. A worrying phenomenon that we owe in part to the warming of the Mediterranean, sometimes 5 to 6°C above normal.

In France, we also fear one of the driest summers ever recorded. Patrick Marlière, meteorologist for Agate Météo, shares his forecasts and concerns for the coming season.

“We have already had a remarkable month of June with heat strokes and especially extremely violent storms as well as hailstorms that we had never seen”, recalls the forecaster. This month of July, “very hot with heat waves”, is also worrying because of the severe drought that is currently affecting the country. “It is not the few stormy showers that will reduce this rainfall deficit”, laments Patrick Marlière.

The meteorologist regrets “a truly exceptional situation throughout France”, where “not a region has been spared, from Brittany to the northeast, from the extreme north to the Pyrenees and as far as the Mediterranean”. He says the drought will mark not only this month of July, but also much of the summer…

Indeed, the forecasts for the month of August are not good either, announcing very hot weeks with, possibly, “a new episode of heat wave between August 3 and 5, with between August 10 and 17 some thunderstorms and then perhaps again a heat stroke for the end of the month”, articulates the expert.

This is, for the time being, what the seasonal forecasts are drawing, which will naturally have to be confirmed in the coming days. “The month of August promises to be almost identical to the month of July, in any case just as hot and dry so we are very worried about the results of this summer of 2022”, warns Patrick Marlière.

Summer promises to be hot, therefore, but autumn is not to be outdone. Meteorological experts are also concerned about possible bad weather caused by the warming of the Mediterranean Sea… What consequences could this have for us?

On the northern half of the country, Patrick Marlière’s main concern lies in the persistence of the drought which could continue to rage “at least until September, and perhaps even until October”.

But here it is: other bad weather threatens the southern half of France. Frequent in autumn and in the first part of winter, Cevennes episodes can occur from Hérault to the Rhone Valley at any time of the year.

These are clouds, instabilities which, in the words of the meteorologist, “rise from the Mediterranean, come up against the Cévennes and pour impressive quantities of water which cause very significant floods”.

These Cévennes episodes are in fact episodes of torrential rain that are sometimes very violent: “Last year we recorded more than 400 mm of water on the reliefs of the Hérault, which corresponds to six months of precipitation in the north of France”, recalls the director of Agate Météo.

What does this have to do with sea warming? “The Mediterranean has never been so hot, since it is close to 30°C, and the Cévennes episodes which are triggered mainly according to its temperature. If they ever start a little early, we could have thunderstorms extremely violent in the south of France”, worries the forecaster. “It’s a bit of fear for September and October,” he says.

“This summer’s trend seems to be confirmed, it seems well set on the weather forecast so we can be worried about the month of September, but we keep a small degree of uncertainty about the month of October”, explains the specialist to Planet. What do we know about the possible heat waves that could overwhelm the country at the beginning of autumn?

No, France will probably not face a heat wave in the fall. “Pretty beautiful months of September, we have them, we have had them and we will still have them, but with strong heat it is not frequent at all. It would be exceptional”, notes Patrick Marlière.

“It’s difficult to say that far in the forecast, but the seasonal forecast models are based on a few relevant parameters which tell us that the temperatures are going to be 1 to 2 degrees above normal for the season, that the precipitation will be extremely short and that the sunshine may be excessive”, he summarizes for the first month of the meteorological autumn which, let us remember, begins on September 1.

“The trend of a hot, dry month of September, which would therefore perhaps be with an episode of heat wave, would be exceptional, we may be close to it, at least in the Mediterranean regions”, concludes our expert. weather report.