Chipmunks in Illinois in October
Yes, October is a good month to see chipmunks in Illinois. It is the 4th busiest month of the year, with 2,416 of the 24,549 sightings logged across the year (9.8%), based on verified iNaturalist records.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 28, 2026.
Good month for chipmunks in Illinois
9.8%
of yearly sightings
2,416
records in October
#4
busiest month of 12
24,549
verified records a year
September 10.2%, October 9.8%, November 7.1%. Busiest month is April at 14.8%.
24,549 verified observations of chipmunks in Illinois, recorded across 12 months of the year on iNaturalist.
When chipmunks 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% |
Chipmunks 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 |
In Illinois, October carries 9.8% of the year's chipmunks sightings, about 1.5 points above an even month-to-month split. That makes it the 4th busiest of the twelve months, out of 12 months with recorded activity.
Activity holds steady between September and October, and it heads toward November (7.1%) after. The busiest month is April (14.8%), so if timing is flexible, that window is the safer bet.
The chipmunks most often recorded in Illinois are Eastern Gray Squirrel, Eastern Chipmunk and Eastern Fox Squirrel. Those counts are annual totals rather than a October split, so treat them as which species you are likely to encounter, while the month figures above show how many sightings fall in October itself.
Which chipmunks you are most likely to see
- Eastern Gray Squirrel13,881 records
- Eastern Chipmunk4,523 records
- Eastern Fox Squirrel3,453 records
- Groundhog1,523 records
- Thirteen-lined Ground Squirrel510 records
- Southern Flying Squirrel177 records
Plan your chipmunk 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 chipmunk viewing area.
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Stay nearbyStay near Lewis & Clark National Historic Trail
Compare hotels, cabins and lodges close to the best chipmunk viewing area in Illinois.
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Broader backupBook a chipmunk tour in Illinois
Compare guided wildlife tours, boat trips and nature experiences if you want a second travel network beyond the live widget.
Frequently asked questions
Can you see chipmunks in Illinois in October?+
Yes. October accounts for 2,416 of the 24,549 verified chipmunks sightings logged in Illinois across the year, which is 9.8% of the annual total.
Is October a good time to see chipmunks in Illinois?+
October is the 4th busiest month. It is workable, though April and May is the stronger window for a reliable sighting.
What month is best for chipmunks in Illinois?+
April is the single busiest month, with the broader peak running through April, May and September, based on 24,549 verified observations.
Which chipmunks are you most likely to see in Illinois?+
The most-recorded species in Illinois are Eastern Gray Squirrel, Eastern Chipmunk and Eastern Fox Squirrel, based on all-time iNaturalist counts.