BUTTE — A gradual warmup is ahead for southwest Montana through mid-week, with daily chances for isolated thunderstorms centered on the mountains and valleys around Butte, Bozeman, Dillon, and West Yellowstone. A more widespread round of showers and storms arrives Thursday, followed by cooler, breezier, and more unsettled weather for the weekend.
TUESDAY
Southwest Montana will see the greatest chance for showers and thunderstorms across the region, especially near the Montana-Idaho border and surrounding mountain ranges. Areas around Dillon, West Yellowstone, and Ennis have the best opportunity for afternoon and evening storms, while Butte and Bozeman may see isolated development later in the day. Some storms could produce gusty winds due to very dry low-level air. Elsewhere across north-central and central Montana, conditions remain mostly dry with seasonable temperatures.
WEDNESDAY
Thunderstorm chances shift north and east, focusing along and south of Interstate 90. Butte, Bozeman, Three Forks, Livingston, and nearby valleys will have the best opportunity for isolated afternoon and evening showers and thunderstorms. A few storms may produce strong wind gusts and little rainfall. Temperatures continue a gradual warming trend, with many lower elevations reaching the upper 80s.
THURSDAY
Shower and thunderstorm coverage increases across all of southwest Montana and expands into central and north-central sections of the state. Butte, Bozeman, Helena, Dillon, and surrounding valleys can expect scattered storms during the afternoon and evening. A few stronger storms may develop near the Continental Divide and adjacent foothills, bringing strong winds and locally heavy rainfall. Temperatures peak for the week, with many locations reaching the upper 80s to lower 90s.
FRIDAY
An approaching Pacific trough keeps scattered shower and thunderstorm chances in the forecast. Warm temperatures linger, but increasing southwest winds signal an approaching pattern change. Storms remain possible throughout southwest Montana, particularly during the afternoon and evening.
SATURDAY
Cooler air filters into the region as the trough moves inland. Breezy conditions develop across southwest Montana, including the I-90 corridor from Butte to Bozeman. Scattered showers and thunderstorms remain possible, especially over the mountains and adjacent valleys. Temperatures fall back closer to seasonal averages.
SUNDAY
The most widespread precipitation chances of the period arrive as the upper-level trough crosses the region. Showers and thunderstorms are expected across much of southwest Montana, including Butte, Bozeman, Helena, Dillon, Livingston, and West Yellowstone. Cooler temperatures and breezy conditions will continue through the day.
EARLY NEXT WEEK
An unsettled pattern is expected to persist with below-normal temperatures, periodic showers, and continued chances for breezy conditions across southwest Montana and surrounding areas. The exact distribution of rainfall will depend on how the weekend storm system evolves, but active weather is likely to continue into early September.
