MISSOULA — A chilly start to the week will be followed by a brief stretch of warm and dry weather across western and northwestern Montana. by midweek, there are increasing chances for showers, thunderstorms, and cooler temperatures as a more active pattern returns during the second half of the week.
MONDAY
The coldest morning of the season so far is expected across many valleys, especially higher elevation locations. Widespread frost is likely around Seeley Lake, Georgetown Lake, Drummond, and other colder valleys where temperatures dip into the upper 20s and lower 30s. Patchy frost may even develop in parts of the western Missoula Valley and Stevensville. After the chilly start, sunshine and dry air will help temperatures rebound into the upper 70s and lower 80s during the afternoon.
TUESDAY
Warm and dry conditions continue as high pressure remains in control. Valley locations from Missoula to Kalispell can expect highs in the 80s with low humidity levels during the afternoon. By late day, the ridge begins to weaken, bringing increasing clouds and the chance for scattered showers and isolated thunderstorms. Any storms that develop could produce gusty and erratic outflow winds due to high cloud bases and a dry lower atmosphere.
WEDNESDAY
A stronger weather disturbance moves into the Northern Rockies, bringing a noticeable increase in showers, thunderstorms, and gusty winds. Storm coverage will become more widespread across western Montana, including the Flathead, Missoula, Bitterroot, and Mission valleys. Some storms may produce locally heavy rainfall, and wetting rains become increasingly likely across much of the region by afternoon and evening.
THURSDAY
An active weather pattern remains in place with scattered showers, thunderstorms, and breezy conditions. Temperatures trend cooler as cloud cover increases and periodic precipitation moves through. Many locations stand a good chance of receiving beneficial rainfall, helping to ease late-summer dryness.
FRIDAY
Cooler-than-normal temperatures continue with additional rounds of showers possible across much of western and northwestern Montana. While not a washout, expect intervals of clouds, scattered precipitation, and occasional breezy conditions through the day.
NEXT WEEKEND
Confidence is increasing that a broad trough of low pressure will remain anchored over the Pacific Northwest. This setup favors continued southwesterly flow across the Northern Rockies, keeping temperatures slightly below seasonal averages while supporting daily opportunities for showers and thunderstorms. Missoula, Kalispell, Libby, Polson, and surrounding areas are likely to remain in a cooler and more unsettled pattern with above-normal precipitation chances through the weekend.
