Updated October 2026
Best Time to Visit Illinois State Parks & National Parks
Illinois has 3 National Park Service units that report visitation. Below, each is ranked by annual visits, with the month our data recommends for the best balance of light crowds, comfortable weather and daylight. Crowds peak in summer almost everywhere — the recommended months show where the quieter shoulder seasons fall.
The 24 Illinois state parks are listed in their own section below the national park table. Crowd levels are shown for national park units only; for state parks the best month reflects weather and daylight.
Illinois parks on the map
Click a marker for the park page, or use Where to stay in the table.
Ways to pick a Illinois park
Quietest months
- Lincoln Home — January
- Emmett Till and Mamie Till-Mobley — January
- Pullman — December
Most-visited
- Lincoln Home — 154,522 visits
- Pullman — 31,961 visits
- Emmett Till and Mamie Till-Mobley — 3,763 visits
| Park | Annual visits | Best time | Busiest | Quietest | Stays |
|---|---|---|---|---|---|
| Lincoln HomeNational Historic Site | 154,522 | September | May | Jan | Where to stay → |
| PullmanNational Historical Park | 31,961 | September | Jul | Dec | Where to stay → |
| Emmett Till and Mamie Till-MobleyNational Monument | 3,763 | October | Jun | Jan | Where to stay → |
Illinois State Parks
24 state parks, with the month that usually brings the most comfortable weather and the longest days, where a nearby weather record exists.
- Adeline Jay Geo-Karis Illinois Beach State ParkUsually best in June · about 3,200 acresOfficial park page
- Beaver Dam State ParkUsually best in September · about 700 acresOfficial park page
- Buffalo Rock State ParkUsually best in June · about 300 acresOfficial park page
- Castle Rock State ParkUsually best in June · about 2,000 acresOfficial park page
- Cave-in-Rock State ParkUsually best in September · about 190 acresOfficial park page
- Chain O' Lakes State ParkUsually best in June · about 5,100 acresOfficial park page
- Channahon State ParkUsually best in JuneOfficial park page
- Delabar State ParkUsually best in September · about 110 acresOfficial park page
- Edward R. Madigan State ParkUsually best in September · about 970 acresOfficial park page
- Fox Ridge State ParkUsually best in September · about 1,700 acresOfficial park page
- Frank Holten State ParkUsually best in May · about 1,000 acresOfficial park page
- Gebhard Woods State ParkUsually best in September · about 31 acresOfficial park page
- Horseshoe Lake State Park (Madison County)Usually best in May · about 3,300 acresOfficial park page
- Illini State ParkUsually best in June · about 160 acresOfficial park page
- Jubilee College State ParkUsually best in September · about 48 acresOfficial park page
- Lake Murphysboro State ParkUsually best in September · about 950 acresOfficial park page
- Lowden State ParkUsually best in June · about 200 acresOfficial park page
- Matthiessen State ParkUsually best in June · about 1,900 acresOfficial park page
- NauvooUsually best in September · about 150 acresOfficial park page
- Pere Marquette State ParkUsually best in May · about 120 acresOfficial park page
- Rock Cut State ParkUsually best in August · about 3,100 acresOfficial park page
- Siloam Springs State ParkUsually best in September · about 5,900 acresOfficial park page
- Spitler Woods State Natural AreaUsually best in September · about 40 acresOfficial park page
- William G. Stratton State ParkUsually best in SeptemberOfficial park page
State park listings come from the Illinois state park agency. Boundaries and acreage come from the USGS Protected Areas Database. Best-month estimates use NOAA 1991-2020 climate normals and computed daylight.
Illinois park crowd calendar (3 parks, all 12 months)
Download the full best-months table for all 3 of Illinois's national parks — each park's month-by-month crowd index (1.0 = its average month), busiest and quietest months, and Best-Time-to-Visit score. Built from NPS visitation data. Enter your email to download. No spam, unsubscribe anytime.
Where to stay near Illinois's national parks
Find hotels, cabins and vacation rentals across Illinois to base your national-park trip — live availability and prices.
Top-rated places to stay near Illinois national parks
Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.
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