Each year, about 503 billion cubic meters of water from rain and snow in Metropolitan France return to the atmosphere, making up 60 percent of the total, according to Eaufrance, the public water information service. This means that six out of every ten drops of rain or snow never reach the ground but instead return to the sky through evaporation and evapotranspiration, a process that includes both water evaporating from the soil and that released by plants. This happens particularly in autumn, when groundwater recharge begins. A portion of the rain infiltrates the soil, while another part flows into rivers, but the largest share—314 billion cubic meters—evaporates annually. Evapotranspiration has increased by about 17 percent since 1970, according to recent data. To understand the scale of this evaporation, consider that 1 millimeter of rain over 1 square meter equals 1 liter of water. Using this, 314 billion cubic meters of evaporation equates to roughly 577 millimeters of rain spread over France's surface area of about 544,000 square kilometers. In contrast, the 6 billion cubic meters of water consumed or evaporated by human activities is much smaller, equivalent to about 12 millimeters of rain. This shows that natural evapotranspiration far exceeds human-related water use by more than 50 times. The remaining 40 percent of rainfall, known as "effective rain," is the water that reaches the ground and contributes to runoff and groundwater recharge. According to Eaufrance, 120 billion cubic meters infiltrate the soil and 80 billion flow directly into rivers, meaning that groundwater receives about one and a half times the volume that flows into rivers. This infiltrated water renews underground reserves before eventually reaching surface waters through springs. Ultimately, about 176 billion cubic meters flow into the sea, with 18 billion leaving the country, three times the amount consumed by human activities. There is some variation in the numbers reported. The Ministry of Ecological Transition cites 512 billion cubic meters per year for the period 1981–2010, while Eaufrance lists 503 billion. The difference of 9 billion cubic meters is likely due to the reference periods used. Despite this, the two figures are very close when converted to millimeters of rainfall. The annual rainfall record in Sewen, Haut-Rhin, reached 2,282 millimeters—over twice the national average—highlighting the variability in precipitation across the country. These measurements are gathered by Météo-France using rain gauges, radars, and volunteer observers. As the hydrological year begins in September, each autumn rainfall contributes to the recharge of groundwater, which is crucial for maintaining water resources throughout the year.