The National Weather Service has placed 14 counties across eastern Montana under Heat Advisories through 6 PM MDT Friday, as temperatures climb into the 90s alongside elevated humidity levels that increase the risk of heat-related illness.
The advisories cover a broad swath of the state’s eastern plains and Hi-Line corridor. One alert encompasses Daniels, Dawson, Eastern Roosevelt, Northern Phillips, Northern Valley, Prairie, Richland, Sheridan, Western Roosevelt, and Wibaux counties, where temperatures are forecast in the 90s. A second advisory targets Central and Southeast Phillips, Central and Southern Valley, Garfield, and McCone counties, where readings are expected to reach the mid-90s.
The combination of heat and humidity is the core concern. Eastern Montana’s high plains typically see dry summer heat, making the added moisture notable. The National Weather Service warns that hot temperatures paired with high humidity may cause heat illnesses, including heat exhaustion and heat stroke, particularly among vulnerable populations such as the elderly, young children, and those working or exercising outdoors.
Both advisories expire at 6 PM MDT this evening, but residents are urged to take precautions through the hottest part of the afternoon. The National Weather Service advises drinking plenty of fluids, staying in air-conditioned spaces, and avoiding prolonged sun exposure during peak heat hours. Authorities specifically warn against leaving young children or pets in unattended vehicles — car interiors can reach lethal temperatures within minutes, even on days that feel only moderately warm outside.
The affected region is sparsely populated rangeland and agricultural country stretching from the Canadian border south toward the Yellowstone River valley. Communities such as Sidney, Glendive, Wolf Point, and Malta fall within or near the advisory zones. Residents in these areas without reliable access to air conditioning are encouraged to seek cooling centers or other shaded, ventilated spaces during afternoon hours.
For the latest conditions in the region, see the Billings weather forecast, which tracks temperature trends across south-central Montana and the broader eastern plains corridor. Those traveling through the Hi-Line corridor can also reference the Great Falls weather page for updated conditions to the west.
No watches or warnings beyond the Heat Advisory level are currently active in Montana, according to the National Weather Service. Forecasters have not indicated whether the heat pattern will persist into the weekend, and residents should monitor local NWS forecasts for updates as conditions evolve.