The French Geological Survey and Mining Research Office (BRGM) released its monthly bulletin on September 8, highlighting that groundwater levels continue to be below normal. As of September 1, 61 percent of monitoring points recorded levels lower than the average for the month, with 90 percent of those levels still declining. This situation follows an unusual summer, which the National Institute of Statistics and Economic Studies (Insee) estimates may reduce economic growth by approximately 0.1 percentage points in 2026. Between mid-June and the end of August, Metropolitan France experienced 53 days of heatwaves, split into three periods. The third, which lasted continuously from July 28 to August 19, was particularly long. In comparison, the year 2025 had 27 heatwave days, while the previous record was 31 days in 2022. Agriculture is the main sector affected by the extreme heat. The Insee predicts a 4 percent drop in agricultural production volume in 2026, including fishing and forestry, with about 3 percentage points of that decline linked to the heat. Agriculture accounts for around 3 percent of France's gross domestic product (GDP), and the drop in production translates almost entirely into lost economic value, affecting annual growth by about 0.1 percentage points. Spring crops are the most impacted, with Agreste estimating grain maize production to fall to 9 million tons—35 percent less than in 2025. Of that decline, 19 percent is attributed to the heatwave, while the remaining 21 percent is due to a reduction in the area cultivated. Silage maize is estimated at 11.4 million tons, a 27 percent decrease from the previous year. By August 20, the cumulative growth of permanent pastures was 36 percent below the reference average. Wine production is expected to reach around 34 million hectoliters, down from 36 million in 2025. While repeated heatwaves and droughts have reduced potential yields, part of the decline is also due to a reduction in cultivated areas, according to the Insee. The Insee compares this situation to the 2003 heatwave, which reduced plant production and subtracted 0.3 percentage points from GDP growth. The impact of this year's heatwaves is expected to be less severe because winter crops, such as straw cereals, were less affected by the heat, which occurred at the end of their growing cycle. The electricity sector has also been impacted by the heat. Compared to the same periods in 2025, electricity consumption increased by 4.0 percent during the first heatwave, 5.6 percent during the second, and 3.1 percent during the third. National electricity production rose during the first two episodes—by 6.2 percent and then 1.3 percent—but fell by 2.1 percent during the third. The mechanisms behind these changes vary. During the second heatwave, the increase in production came solely from thermal power plants, which compensated for the drop in nuclear power with the help of solar power. During the third, the Insee attributes the decline in production entirely to a reduction in nuclear power, partially offset by fossil fuel-based thermal power plants and, to a lesser extent, solar power. In construction, the long-term effects are mainly seen in public works projects. French industrial production was not significantly affected by heatwaves until 2025. On the household level, the summer boosted purchases of fans, air conditioners, drinks, and ice creams. According to the Insee, these trends do not significantly impact the broader economy. However, in the Southwest region, wildfires have led to a sharp increase in the number of employees working reduced hours. The Insee cautions that these are short-term effects and do not necessarily indicate medium-term impacts. These estimates are based on incomplete data available at the beginning of September, and further effects cannot be ruled out in sectors typically unaffected by heat. The Insee suggests that normal conditions may return next summer, predicting a rebound in agricultural production in 2027. This recovery would likely support economic growth starting in the fourth quarter of 2026. The upcoming BRGM bulletins will help track the replenishment of groundwater levels this autumn.