Will France experience a heat wave of up to 45°C from 6 July?

A viral post on social media has sparked widespread discussion about potential extreme heat in France, suggesting temperatures could reach up to 45 degrees Celsius starting July 6. The claim was shared widely online, including on the Instagram account “Dormir au courant,” which posted a map of France shaded in deep red, accompanied by the statement that a second, more intense heatwave would begin in early July, with temperatures potentially reaching 45°C. This image gained significant attention, receiving nearly 172,000 likes on Instagram alone. However, experts have since clarified that this information is misleading and not supported by reliable meteorological sources. The post attributed its claims to two external sources: Meteologix, a Swiss weather forecasting website, and Selectra, an energy comparison service. Both organizations have denied any involvement in producing the specific forecast cited in the viral content. Meteologix confirmed that the map shown in the post does not originate from their services, while Selectra stated that the map referenced an unrelated heatwave that occurred earlier in May. These clarifications indicate that the viral post relied on misattributed or outdated data rather than current and accurate forecasts. Despite these inaccuracies, there is evidence supporting the general idea of a new wave of high temperatures arriving in France. According to Météo-France, a progressive increase in temperatures is anticipated, beginning in southern regions before spreading across much of the country. Temperatures above 30°C are expected over most of the territory, with some areas in the south possibly experiencing 35°C or higher. Additionally, the heat is likely to intensify further during the following week due to the influence of an anticyclone. However, the precise extent of this heatwave remains uncertain, and it is currently impossible to confirm whether temperatures will reach as high as 45°C. Monique Barbut, France’s Minister for Ecological Transition, mentioned on France Inter that there is a strong likelihood of a return of high temperatures between July 6 and 14. Her comments suggest that a heatwave is indeed expected but do not specifically endorse the figure of 45°C. Instead, her remarks focus on the broader probability of elevated temperatures without confirming the extreme numbers highlighted in the viral posts. Experts have pointed out that the figure of 45°C comes from a single deterministic model known as the Global Forecast System (GFS), used by American meteorologists. While this model provides reasonably accurate predictions for very short-term forecasts, its reliability decreases significantly beyond three days. For longer-range forecasts, meteorologists typically rely on ensemble models such as those produced by the European Centre for Medium-Range Weather Forecasts (ECMWF). These models generate multiple scenarios based on slight variations in initial conditions, allowing for a more comprehensive assessment of potential outcomes. For the period around July 6, these ensemble models consistently predict warm, dry, and sunny weather. However, they differ regarding the intensity of the heat. A few rare scenarios suggest temperatures comparable to those experienced during June's heatwave, while others anticipate values close to seasonal averages. The most likely trend indicates temperatures approximately 4°C to 5°C above normal levels. Therefore, the 45°C figure represents an extreme scenario derived from one model and should not be presented as a definitive forecast for France starting July 6. As the anticipated heatwave approaches, it is crucial for individuals and communities to remain informed and prepared. While the exact temperature extremes remain uncertain, the possibility of prolonged high temperatures underscores the importance of staying hydrated, avoiding excessive sun exposure, and being mindful of vulnerable populations such as the elderly and young children. Authorities continue to monitor the situation closely, ensuring that appropriate measures are taken to mitigate the risks associated with rising temperatures.