Mammoth Cave National Park in September
September at Mammoth Cave National Park averages a daytime high near 85°F and an overnight low around 60°F, with about 4" of precipitation. Visitation runs about 1× the park's average month, which makes September an average month here.
- Average low
- 60°F
- Average high
- 85°F
Range across the year: 29°F to 91°F
- Precipitation
- 4.0 in
- Daylight
- 12.2 hours
Roughly 9% of the park's yearly visitors come in September: about 49,000 recreation visits in a typical year, based on National Park Service monthly counts from 1979 to 2025.
That makes September the 8th-busiest of the park's twelve months, sitting between the July peak (2×) and the January low (0.3×).
September is our recommended month at Mammoth Cave: pleasant weather with noticeably thinner crowds (shoulder season).
The daily average of about 73°F is a comfortable range for hiking and being outdoors all day. These figures are 1991–2020 NOAA climate normals from the nearest station, about 4.7 miles from the park.
Because June, July and August together draw about 42% of annual visitors, choosing September instead steps outside that summer crush — the single biggest lever on how crowded the park feels.
You'll have about 12.2 hours of daylight in September to explore — between the 9.5-hour midwinter low and the 14.5-hour summer high.
Park-wide, 2025 drew 660,734 recreation visits, down 11.6% from 747,042 in 2024.
Across the past decade overall visitation has risen about 27.1%, so a September visit is likely to feel busier than it did a few years ago.
How September compares with the months around it
| Month | Avg high / low | Crowds | Best-time score |
|---|---|---|---|
| August | 90°F / 67°F | 1.4× Busy | 41 Poor |
| September | 85°F / 60°F | 1.0× Average | 65 Good |
| October | 74°F / 49°F | 1.1× Average | 60 Good |
All twelve months at Mammoth Cave, with the best time to visit.
Things to do at Mammoth Cave in September
The National Park Service tags 11 Mammoth Cave activities for fall. Here are 8 of them. Each links to the park's own page for it.
- Explore Wildflowers at Cedar Sink · 45-60 minutes
- Attend a Ranger-led Program · 10-60 minutes
- Become a Mammoth Cave Junior Ranger
- Cave Tours · 1-6 hours · reservation required
- Mammoth Cave Railroad Bike and Hike Trail
- Ride the Big Hollow Trail
- See the Stars
- Take a Ridge-top Walk to Sunset Point · 30-60 minutes
Frequently Asked Questions
September averages a daytime high near 85°F and an overnight low around 60°F at Mammoth Cave National Park, with about 4 inches of precipitation. These are 1991–2020 NOAA climate normals from the nearest station, about 4.7 miles from the park, so conditions inside the park can differ, especially at other elevations.
September is average at Mammoth Cave National Park (about 1.0× the average month). Our best-time score rates it "Good" at 65/100. September is our recommended month for this park.
The busiest month is July and the quietest is January. September sits at about 1.0× the park's average, or 9% of annual visitation.
A typical September sees about 49,000 recreation visits at Mammoth Cave National Park, based on National Park Service monthly counts from 1979–2025.
Where to stay near Mammoth Cave in September
Booking a September trip to Mammoth Cave National Park? Compare hotels, cabins and vacation rentals near the park with live September availability and prices.
Top-rated places to stay near Mammoth Cave
Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.
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See the full ranking of the best national parks to visit in September.
Source: National Park Service Visitor Use Statistics (1979–2025), NOAA NCEI Climate Normals 1991–2020. Updated 2026-10-11.