Tree Frogs in Illinois in May
Yes, May is one of the best months to see tree frogs in Illinois. It is the 2nd busiest month of the year, with 1,321 of the 8,972 sightings logged across the year (14.7%), 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.
Peak month for tree frogs in Illinois
14.7%
of yearly sightings
1,321
records in May
#2
busiest month of 12
8,972
verified records a year
April 18.2%, May 14.7%, June 10.5%. Busiest month is April at 18.2%.
8,972 verified observations of tree frogs in Illinois, recorded across 12 months of the year on iNaturalist.
When tree frogs are recorded in Illinois
Peak month
April
1,636 records (18.2% of the year)
| Month | Observations | Share |
|---|---|---|
| January | 17 | 0.2% |
| February | 137 | 1.5% |
| March | 951 | 10.6% |
| Aprilpeak | 1,636 | 18.2% |
| Maypeak | 1,321 | 14.7% |
| June | 944 | 10.5% |
| July | 805 | 9% |
| August | 862 | 9.6% |
| September | 937 | 10.4% |
| Octoberpeak | 1,232 | 13.7% |
| November | 111 | 1.2% |
| December | 19 | 0.2% |
Tree Frogs you are most likely to see
| Species | Verified observations |
|---|---|
| Blanchard's Cricket Frog | 2,560 |
| Gray Treefrog | 1,132 |
| Boreal Chorus Frog | 1,103 |
| Spring Peeper | 679 |
| Green Treefrog | 659 |
| Cope's Gray Tree Frog | 502 |
| Bird-voiced Treefrog | 195 |
| Western Chorus Frog | 102 |
In Illinois, May carries 14.7% of the year's tree frogs sightings, about 6.4 points above an even month-to-month split. That makes it the 2nd busiest of the twelve months, out of 12 months with recorded activity.
Activity is easing off from April (18.2%) into May, and it heads toward June (10.5%) after. This is right inside the peak window, so May is one of the surest months to plan a trip around.
The tree frogs most often recorded in Illinois are Blanchard's Cricket Frog, Gray Treefrog and Boreal Chorus Frog. Those counts are annual totals rather than a May split, so treat them as which species you are likely to encounter, while the month figures above show how many sightings fall in May itself.
Which tree frogs you are most likely to see
- Blanchard's Cricket Frog2,560 records
- Gray Treefrog1,132 records
- Boreal Chorus Frog1,103 records
- Spring Peeper679 records
- Green Treefrog659 records
- Cope's Gray Tree Frog502 records
Plan your tree frog 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 tree frog viewing area.
Booking.com
Stay nearbyStay near Lewis & Clark National Historic Trail
Compare hotels, cabins and lodges close to the best tree frog viewing area in Illinois.
Viator
Broader backupBook a tree frog 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 tree frogs in Illinois in May?+
Yes. May accounts for 1,321 of the 8,972 verified tree frogs sightings logged in Illinois across the year, which is 14.7% of the annual total.
Is May a good time to see tree frogs in Illinois?+
May is one of the best months. It ranks 2nd of the year and sits inside the peak window of April, May and October.
What month is best for tree frogs in Illinois?+
April is the single busiest month, with the broader peak running through April, May and October, based on 8,972 verified observations.
Which tree frogs are you most likely to see in Illinois?+
The most-recorded species in Illinois are Blanchard's Cricket Frog, Gray Treefrog and Boreal Chorus Frog, based on all-time iNaturalist counts.
See tree frogs in Illinois in other months
More places to see tree frogs
More wildlife in Illinois