Heatwave in Iceland

From 13-22 May 2025, Iceland experienced an unusual heatwave with temperatures reaching or exceeding 20°C at various locations, making it the most significant May heatwave ever recorded in Iceland.  

The Copernicus Sentinel-3 mission was able to obtain an accurate measurement of the land surface temperature of the ground on 17 May, when temperatures reached the peak. 

The image was generated by using the mission’s Sea and Land Surface Temperature Radiometer instrument. While weather forecasts use predicted air temperatures, this satellite instrument measures the real amount of energy radiating from Earth. Therefore, this image shows the actual temperature of the land’s surface, which is usually significantly hotter than air temperatures.