Indiana Dunes National Park in September
September at Indiana Dunes National Park averages a daytime high near 74°F and an overnight low around 56°F, with about 3.7" of precipitation. Visitation runs about 1.3× the park's average month, which makes September a busy month here.
- Average low
- 56°F
- Average high
- 74°F
Range across the year: 18°F to 82°F
- Precipitation
- 3.7 in
- Daylight
- 12.3 hours
Roughly 11% of the park's yearly visitors come in September: about 254,000 recreation visits in a typical year, based on National Park Service monthly counts from 1979 to 2025.
That makes September the 4th-busiest of the park's twelve months, sitting between the July peak (2.2×) and the January low (0.4×).
On our Best Time to Visit score September rates 65/100 ("Good"). Our recommended month is October: the lightest crowds of the park's good-weather months.
The daily average of about 65°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 0.6 miles from the park.
Because June, July and August together draw about 49% 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 12.3 hours of daylight in September to explore — between the 9-hour midwinter low and the 15-hour summer high.
Park-wide, 2025 drew 2,629,497 recreation visits, down 2.8% from 2,705,209 in 2024.
Across the past decade overall visitation has risen about 40.6%, 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 | 80°F / 63°F | 1.8× Very busy | 54 Fair |
| September | 74°F / 56°F | 1.3× Busy | 65 Good |
| October | 62°F / 45°F | 0.9× Average | 58 Fair |
All twelve months at Indiana Dunes, with the best time to visit.
Things to do at Indiana Dunes in September
The National Park Service tags 10 Indiana Dunes activities for fall. Here are 8 of them. Each links to the park's own page for it.
- 1966 Hiking Challenge · 1-5 hours
- Horseback Riding at Indiana Dunes · reservation required
- Become an Indiana Dunes Junior Ranger · 30 minutes
- Birding at Indiana Dunes National Park
- Diana Dunes Dare · 40-100 minutes
- Full Day Expeditions · 6-24 hours
- Half Day Adventures · 2-8 hours
- One Hour Excursions · 1-4 hours
Frequently Asked Questions
September averages a daytime high near 74°F and an overnight low around 56°F at Indiana Dunes National Park, with about 3.7 inches of precipitation. These are 1991–2020 NOAA climate normals from the nearest station, about 0.6 miles from the park, so conditions inside the park can differ, especially at other elevations.
September is busy at Indiana Dunes National Park (about 1.3× the average month). Our best-time score rates it "Good" at 65/100. Our recommended month is October.
The busiest month is July and the quietest is January. September sits at about 1.3× the park's average, or 11% of annual visitation.
A typical September sees about 254,000 recreation visits at Indiana Dunes National Park, based on National Park Service monthly counts from 1979–2025.
Where to stay near Indiana Dunes in September
Booking a September trip to Indiana Dunes National Park? Compare hotels, cabins and vacation rentals near the park with live September availability and prices.
Top-rated places to stay near Indiana Dunes
Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.
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Visiting Indiana Dunes in September?
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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.