Paris has set a new record for the number of days with temperatures reaching or exceeding 25°C in a single year. This Monday, the city recorded its 99th such day of 2026, with a provisional maximum temperature of 26.8°C. This surpasses the previous record of 98 days set in 2018. On Tuesday, September 15, Paris is expected to reach its 100th day of the year with temperatures at or above 25°C, a milestone that marks an unusual trend in recent years. A "heat day" in climatology is defined as any day with a maximum temperature of 25°C or higher. A "day of intense heat" is when temperatures reach 30°C or more. These thresholds are being crossed earlier each year. For instance, the average date for crossing the 25°C threshold in Paris since 1991 was April 30, but in 2025, this occurred as early as April 5. This year, Paris recorded three days with temperatures above 25°C in April, followed by 13 days in May, and the trend continued through the summer months, with 20 days in June, 29 in July, and 24 in August. This year's heat has been particularly extreme, with temperatures expected to reach up to 32°C in Paris on Tuesday. Other regions in France, such as Toulouse, Bordeaux, Strasbourg, Bourges, and Lyon, are also experiencing high temperatures, with some areas expecting up to 36°C. However, a shift in air mass is expected to bring a sharp temperature drop starting Wednesday, potentially reducing temperatures by up to 10°C in many regions. Despite this, temperatures are forecast to rise again this weekend, with many areas once again seeing temperatures above 25°C. Late September heat episodes are becoming more common and more intense, a trend linked to global warming. France recently broke its national heat record for September when temperatures reached 40.3°C in Lavaur, Tarn, on September 7. These extreme weather patterns highlight the increasing impact of climate change on temperature trends across the country.