Indiana Dunes National Park in September
Indiana Dunes National Park · crowd + weather almanac
September crowd level
moderate
about 243,000 visits in a
typical September
The 4th-busiest month of the year ·
median of 2016–2025 official NPS counts
September is the 4th-busiest month of the year at Indiana Dunes National Park: about 243,000 recreation visits in a typical September (10% of the year's traffic, and 56% of what the peak month, July, sees). Crowds are middling — noticeably lighter than peak season. Weather-wise, September days at the Indiana Dunes Nl, IN station typically top out around 74°F with nights near 56°F, and about 3.6 inches of precipitation falls over the month.
- Typical September: 242,939 recreation visits (median 2016–2025); the range across those years ran 167,089 (2018) to 405,688 (2017).
- Busier than 8 of the other 11 months.
- 1991–2020 September normals at Indiana Dunes Nl, IN: high 74°F, low 56°F, 3.65 in precipitation, 0.0 in snow.
September weather (1991–2020 normals)
| Typical daytime high | 74°F |
|---|---|
| Typical overnight low | 56°F |
| Precipitation (monthly normal) | 3.65 in |
| Snowfall (monthly normal) | 0.0 in |
| Measured at | Indiana Dunes Nl, IN (USC00124244), 2.4 mi from the park reference point, elev. 680 ft |
Every month at Indiana Dunes
| Month | Typical visits | Crowds | High / Low | Precip |
|---|---|---|---|---|
| January | 71,142 | quiet | 32°F / 18°F | 2.2 in |
| February | 85,577 | quiet | 36°F / 21°F | 2.0 in |
| March | 124,061 | quiet | 46°F / 30°F | 2.3 in |
| April | 122,599 | quiet | 57°F / 40°F | 3.5 in |
| May | 204,925 | moderate | 68°F / 50°F | 4.3 in |
| June | 330,558 | busy | 78°F / 60°F | 4.3 in |
| July | 436,351 | busiest stretch | 82°F / 64°F | 4.0 in |
| August | 397,679 | busiest stretch | 80°F / 63°F | 4.1 in |
| September | 242,939 | moderate | 74°F / 56°F | 3.6 in |
| October | 184,907 | moderate | 62°F / 45°F | 3.8 in |
| November | 95,411 | quiet | 49°F / 34°F | 2.8 in |
| December | 88,593 | quiet | 37°F / 24°F | 2.3 in |