September is an excellent month at Indiana Dunes — it ranks 4th of the twelve here. Expect about 47% fewer visitors than July, the park's peak — 272,078 visits on average. Days run around 74°F by afternoon and 56°F at night, with 12.4 hours of daylight.
September against the park's best
| Month | Verdict | Avg. visits | vs. peak | High | Low | Snow | Daylight |
|---|---|---|---|---|---|---|---|
| September (this page) | Excellent | 272,078 | −47% | 74°F | 56°F | 0" | 12.4 h |
| April (best) | Excellent | 166,419 | −67% | 57°F | 40°F | 0.6" | 13.3 h |
| July (peak crowds) | Good | 509,715 | peak | 82°F | 64°F | 0" | 14.9 h |
Weather figures are for the Porter area — the Indiana Dunes Nl station. Visits are 2021–2025 averages; climate normals cover 1991–2020. Conditions vary across the park; check current status before you go.
Common questions
Is September a good time to visit Indiana Dunes?
Yes — it is one of the best months of the year here. September ranks 4 of 12 at Indiana Dunes on crowds, weather, daylight, and access together.
How crowded is Indiana Dunes in September?
About 272,078 recreation visits on average — 47% below July, the park's peak.
How warm is Indiana Dunes in September?
Average highs around 74°F and lows around 56°F at the Indiana Dunes Nl station.
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