NASA's ECOSTRESS Captures Short-Lived Heat Wave in L.A. Area
A short-lived heat wave that hit the Los Angeles area the week of July 7, 2025, was the first of summer. The heat lingered into the evening hours, as captured by NASA's Ecosystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) instrument.
By nearly 8:45 p.m. local time July 9, surface temperatures in the San Fernando Valley were still over 80 degrees Fahrenheit (27 degrees Celsius). The ECOSTRESS sensor recorded similar temperatures for downtown Pasadena (Figure A) and parts of Altadena, east of NASA's Jet Propulsion Laboratory, which manages the mission. In these data visualizations, dark red indicates higher temperatures, while areas in blue and green are cooler. Coastal regions remained significantly cooler than inland areas.
The ECOSTRESS instrument measures thermal infrared emissions from Earth's surface. This enables researchers to monitor plant health, the progress of wildfires, land surface temperatures, and the burn risk to people from hot surfaces such as asphalt. Land surface temperatures are hotter than air temperatures during the day. Air temperatures, which are measured out of direct sunlight, are usually what meteorologists report in a weather forecast.
The instrument launched to the space station in 2018. Its primary mission is to identify plants' thresholds for water use and water stress, giving insight into their ability to adapt to a warming climate. NASA's Jet Propulsion Laboratory in Southern California built and manages the ECOSTRESS mission for the Earth Science Division in the Science Mission Directorate at NASA Headquarters in Washington. ECOSTRESS is an Earth Venture Instrument mission; the program is managed by NASA's Earth System Science Pathfinder program at NASA's Langley Research Center in Hampton, Virginia.
More information about ECOSTRESS is available here: