How Crowded Is Lowell in September?
September is a very quiet month at Lowell National Historical Park, running about 0.5× the park's average month — roughly 4% of the year's visitors come in September. That puts it between the July peak and the December low. Overall our best-time score rates September as "Excellent" for a visit. Typical September weather averages a high near 76°F and a low around 52°F, with about 3.9" of precipitation. You'll get about 12.3 hours of daylight to explore.
Frequently Asked Questions
September is very quiet at Lowell National Historical Park (about 0.5× the average month). Our best-time score rates it "Excellent". The single best month overall is September.
The busiest month is July and the quietest is December. September sits at about 0.5× the park's average, or 4% of annual visitation.
Source: National Park Service Visitor Use Statistics (1979–2025), NOAA NCEI Climate Normals 1991–2020. Updated 2026-06-20.