As Montana warms, Missoula’s first heat map reveals hidden hotspots

Missoula County, Montana now has its first heat map, built last summer when volunteers drove around with sensors tracking temperature and humidity. A nonprofit called Climate Smart Missoula worked with the city and county on the project, using federal funding, and the results are now public online. The map found temperatures can swing by nearly 20 degrees Fahrenheit across the county depending on how much tree cover and green space a neighborhood has. Areas with big, mature trees, like the University District and the Rattlesnake neighborhood, stayed noticeably cooler than more built-up areas like downtown or the Northside and Westside. Empty, undeveloped lots also turned out to trap heat, especially when dry and overrun with weeds instead of native plants.

This matters because Missoula's summers are getting hotter, with more 90-degree days each year, and the county's average temperature is projected to rise 4 to 5 degrees by 2050. Montana also has one of the lowest rates of home air conditioning in the country, so homes built for cooler weather may struggle to keep up. If you're in a neighborhood with little shade, your house may be running warmer than one just a few blocks away with more trees.

The mapping project almost lost its funding this year when the Trump administration canceled the federal grant behind it, but local partners and volunteers kept the work going. Missoula was one of 11 U.S. communities that got this kind of heat mapping done in 2025, and it's the first such map for Montana and the surrounding region.