Best Time to See Squirrels in Illinois
April, May and September is the best time to see squirrels in Illinois. Based on 24,549 verified iNaturalist observations, here is exactly when squirrels are most active across the year in Illinois.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 28, 2026.
24,549 verified observations of squirrels in Illinois, recorded across 12 months of the year on iNaturalist.
When squirrels are recorded in Illinois
Peak month
April
3,644 records (14.8% of the year)
| Month | Observations | Share |
|---|---|---|
| January | 1,299 | 5.3% |
| February | 1,309 | 5.3% |
| March | 2,290 | 9.3% |
| Aprilpeak | 3,644 | 14.8% |
| Maypeak | 3,136 | 12.8% |
| June | 2,094 | 8.5% |
| July | 1,284 | 5.2% |
| August | 1,534 | 6.2% |
| Septemberpeak | 2,501 | 10.2% |
| October | 2,416 | 9.8% |
| November | 1,750 | 7.1% |
| December | 1,292 | 5.3% |
Squirrels you are most likely to see
| Species | Verified observations |
|---|---|
| Eastern Gray Squirrel | 13,881 |
| Eastern Chipmunk | 4,523 |
| Eastern Fox Squirrel | 3,453 |
| Groundhog | 1,523 |
| Thirteen-lined Ground Squirrel | 510 |
| Southern Flying Squirrel | 177 |
| American Red Squirrel | 81 |
| Franklin's Ground Squirrel | 5 |
Sightings of squirrels in Illinois peak in April, when 3,644 of the year's 24,549 verified observations are logged — about 14.8% of the annual total. Activity stays high through April, May and September.
The quietest stretch is July, December and January, when squirrels are hardest to find — July sees just 1,284 records. If a reliable sighting matters, plan around the peak window rather than the off-season.
The squirrels you are most likely to encounter in Illinois are Eastern Gray Squirrel, Eastern Chipmunk and Eastern Fox Squirrel — the most-recorded species in the state. Each keeps its own seasonal rhythm, but the month-by-month pattern above reflects every reported sighting together.
Where to go
Best places to see squirrels in Illinois
- Lewis & Clark National Historic Trail — National Historic Trail
- Lincoln Home National Historic Site — National Historic Site
- Emmett Till and Mamie Till-Mobley National Monument — National Monument
- Mormon Pioneer National Historic Trail — National Historic Trail
- New Philadelphia National Historic Site — National Historic Site
- Pullman National Historical Park — National Historical Park
Plan your squirrel trip in Illinois
Start with live tours near Lewis & Clark National Historic Trail, then compare a nearby stay and a broader wildlife backup before you lock in the trip.
GetYourGuide
Live tours nearbySee live tours near Lewis & Clark National Historic Trail
Use the live GetYourGuide widget to compare local departures and activity styles close to the main squirrel viewing area.
Booking.com
Stay nearbyStay near Lewis & Clark National Historic Trail
Compare hotels, cabins and lodges close to the best squirrel viewing area in Illinois.
Viator
Broader backupBook a squirrel tour in Illinois
Compare guided wildlife tours, boat trips and nature experiences if you want a second travel network beyond the live widget.
Gear to see them
Frequently asked questions
What is the best month to see squirrels in Illinois?+
April is the single best month, and the broader peak window runs through April, May and September, based on 24,549 verified iNaturalist observations.
When are squirrels hardest to see in Illinois?+
July is the quietest month for squirrels in Illinois, with only 1,284 verified records.
Are squirrels active year-round in Illinois?+
Squirrels are recorded in 12 of 12 months in Illinois, so they can be seen year-round, with a clear peak in April.
More wildlife in Illinois