Flathead Lake has, by and large, beautiful summer weather. Generally, from July through September (summer in Montana), it tends to be generally dry, with sunshine the norm, with only a few days of clouds and light rain. Yet, despite the sunshine, temperatures are generally not too hot. Look for typical summer days to run from the mid-70’s to the mid 80’s, and not much rain.
Temperatures cool off noticeably, once summer flows into September – although the days are still generally dry and sunny. Fall weather in Montana begins usually sometime in late September and will run into November. During this time, weather can be highly variable – with weeks of Indian summer weather, followed by cold rain, and sometimes snow.
Flathead Lake winters are generally mild compared to other parts of the county, partly due to the “lake effect” from Flathead Lakes’ large body of water. Average snowfall is 74″, with average day time temperatures in the mid 30’s.
Spring is the rainy season in the Flathead. During May and June, Montana tends to receive the most moisture of the year. When this moisture actually happens, it goes a long way towards preventing forest fires.
