How Crowded Is Craters Of The Moon in September?
September is a very busy month at Craters Of The Moon National Monument & Preserve, running about 1.9× the park's average month — roughly 16% of the year's visitors come in September. That puts it between the July peak and the January low. Overall our best-time score rates September as "Fair" for a visit. Typical September weather averages a high near 71°F and a low around 45°F, with about 0.7" of precipitation. You'll get about 12.3 hours of daylight to explore.
Frequently Asked Questions
September is very busy at Craters Of The Moon National Monument & Preserve (about 1.9× the average month). Our best-time score rates it "Fair". The single best month overall is August.
The busiest month is July and the quietest is January. September sits at about 1.9× the park's average, or 16% of annual visitation.
Source: National Park Service Visitor Use Statistics (1979–2025), NOAA NCEI Climate Normals 1991–2020. Updated 2026-06-20.