France braces for more intense heat from this weekend

France is forecast to see more intense heat from this weekend, impacting the south and centre and bringing highs of 35C or above to many regions.

Northern areas may also be affected depending on how conditions develop this week.

Forecast models indicate growing heat from the weekend, peaking during the course of next week, although national forecasters are not (yet) officially calling it a heatwave.

Yesterday (June 30), Météo France meteorologist Patrick Galois told AFP that France is “likely to experience another heatwave starting this weekend.” 

“From Friday and into the weekend, we are once again expecting higher temperatures due to high-pressure conditions moving in from the south of the country… [with temperatures reaching] very high levels, likely exceeding 35C,” he added.

Temperatures are expected to rise from Saturday (July 4) to around 35C in many areas. Then, depending on the model used, highs of 39C are forecast next week, including as far north as Brittany by July 7 by some forecasts..

It comes as the south-east of France continues to face heatwave alerts and national temperatures remain above average for the season in all regions. 

However, while this may be a third heatwave in as many months, it is unlikely to be as intense as June’s record-breaking heat. 

New anti-cylonic winds 

State forecaster Météo France published its updated weather bulletin on Monday (June 29) covering the coming days. 

“The weather pattern over Europe favours the continuation of high-pressure conditions and a warm temperature anomaly across the entire country,” it said.

“However, at this forecast range, it remains difficult to be more precise about the intensity of the heat.” 

Following storms last weekend that cleared the air and brought cool winds across France, a new high-pressure anti-cyclone is poised to travel across Iberia and push these cooler winds north to the British Isles, leading to a new bout of heat in France. 

Once positioned over France, the high-pressure winds produce a ‘heat dome’ effect, trapping and recycling hot air and drastically increasing temperatures both in the day and at night.

Exact conditions depend on the placement of this anti-cyclonic wind. 

For example, Portugal largely avoided June’s heatwave as those anti-cyclonic winds were further north in the Atlantic, but in July the epicentre of the winds will pass over northern stretches of the country, potentially leading to record-breaking temperatures.

If the winds remain closer to the Mediterranean, it is only southern regions that will feel next week’s heatwave, but if they are further north the winds can sweep across the country and bring heat to all regions.

Are highs of 40C possible?

Current models predict that this high-pressure system will impact the south and centre of the country, but may not move north of the Loire or into the north-east. 

This is in contrast to heatwaves in May and June that affected the entire country, particularly the west. 

Forecaster La Chaîne Météo also predicts rising temperatures in the coming days. 

It highlights two weather models in particular, the American GFS and European ECMWF, in its bulletin. 

The American model is more extreme, predicting highs of 35C throughout much of next week and across most of the country. 

This could include temperatures of 36C around Paris and 39C in Brittany, Bordeaux, and Toulouse. In some places, it means temperatures reaching 17C above their typical readings.

By the middle of next week (July 7 and July 8), national average temperatures may reach 27.7C, nearly 8C above average for the season. 

This however remains around 2C below the peaks experienced in June when France recorded all-time national highs for three consecutive days.

This is the most extreme model, and the ECMWF is less intense. 

It predicts heat in the south and centre of the country, but no expansion further north. Temperatures will be warmer than usual in the south – potentially reaching the consistency of a heatwave – but in the north remain no more than slightly above average. 

“The one point of consensus right now is the gradual return of warmer weather starting the weekend of July 4–5,” said the forecaster, with more accurate models available over the weekend. 

How long will this new period of intense heat last?

To date there is no consensus on this.

Last week, Minister for Ecological Transition Monique Barbut highlighted a report that said France could experience a July heatwave peaking around July 14. 

This model however saw temperatures rising from the start of next week (July 6) and not the weekend (July 4).

It means that any temperature peak is likely to come earlier than this, as temperatures begin rising sooner.

Much depends on the movement of the anti-cyclonic winds, but high temperatures will be expected for several days. 

As a reminder, heatwave warnings in France are only implemented when temperatures reach above a certain departmental threshold for three consecutive days. 

This applies to both day- and night-time temperatures, with each department having its own specific temperature limits based on typical local conditions.