Paris was one of the many European cities affected by the recent heat wave record at the end of June and early July 2025.
The Ecostress instrument (NASA’s spatial thermal radiometer experiment) recorded surface temperatures of 23 degrees Celsius at 06.57, local time, of July 1, just at dawn, when temperatures are cooler.
The extreme daytime temperatures, greater than 38 degrees Celsius, forced the authorities to close the top of the Eiffel Tower on July 1 and 2.
In this visualization of ecostress data, dark red indicates higher temperatures, while green and blue indicate lower temperatures. The city is dotted with areas of several apples where surface temperatures exceeded 27 ° C, even around the Eiffel Tower, before 7 am
The Ecostress instrument measures the thermal infrared emissions of the earth’s surface. This allows researchers to monitor plants health, the advancement of forest fires, earthly surface temperatures and the risk of burns for people caused by hot surfaces such as asphalt. Earth’s surface temperatures are higher than those of the air during the day. Air temperatures, which are measured without direct sunlight, are usually the ones that meteorologists report in a weather forecast, reports NASA.
The instrument was launched to the space station in 2018. Its main mission is to identify the thresholds of plants for the use of water and water stress, which provides information on its ability to adapt to global warming.