Analysis Of Temperature Changes and Extreme Heat Events in France, 2000–2024

Abstract

In the last several years, global warming has become more apparent. France, being one of the most climate-sensitive regions in Europe, has been experiencing a clear rise in temperature and frequency of extreme heat, which has severely affected the public health, agricultural, and energy sectors. However, there has not been much systematic quantitative investigation of temperature trends in France over the past 25 years. On that basis, Copernicus ERA5 and ERA5-Land reanalysis datasets are utilized as baseline data sources, along with Météo-France official reports, to conduct a systematic examination of temperature change trends and spatial distribution of heat waves in France between 2000 and 2024. The annual mean temperature, summer mean temperature (JJA), number of hot days (Tmax > 35 °C), and TX90p indices were extracted using the ERA5 reanalysis data, and the trend of change was analyzed while using spatial interpolation and linear fit methods. The findings suggest that the overall warming trend rate in France is approximately 0.46 degrees Celsius per decade over the last 25 years, with the hottest years being 2003 and 2022 for heat waves. The southern coastal and southeastern coastal French areas experience the strongest warming. Generally, there was a high consistency between ERA5 data and Météo-France annual report results, with a very high correlation coefficient of greater than or equal to 0.9, and thus indicated the reliability of reanalysis data as a basis for regional climate monitoring.