Tree Frogs in Illinois in April

Yes, April is one of the best months to see tree frogs in Illinois. It is the 1st busiest month of the year, with 1,636 of the 8,972 sightings logged across the year (18.2%), based on verified iNaturalist records.

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By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 28, 2026.

Blanchard's Cricket Frog photographed in IllinoisIllinois Chorus Frog photographed in IllinoisGray Treefrog photographed in Illinois
Photos by iNaturalist observers, used under Creative Commons.

Peak month for tree frogs in Illinois

18.2%

of yearly sightings

1,636

records in April

#1

busiest month of 12

8,972

verified records a year

March 10.6%, April 18.2%, May 14.7%. Busiest month is April at 18.2%.

Best months: April, May, October

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)

Quietest month

January

17 records

MonthObservationsShare
January170.2%
February1371.5%
March95110.6%
Aprilpeak1,63618.2%
Maypeak1,32114.7%
June94410.5%
July8059%
August8629.6%
September93710.4%
Octoberpeak1,23213.7%
November1111.2%
December190.2%

Tree Frogs you are most likely to see

SpeciesVerified observations
Blanchard's Cricket Frog2,560
Gray Treefrog1,132
Boreal Chorus Frog1,103
Spring Peeper679
Green Treefrog659
Cope's Gray Tree Frog502
Bird-voiced Treefrog195
Western Chorus Frog102

In Illinois, April carries 18.2% of the year's tree frogs sightings, about 9.9 points above an even month-to-month split. That makes it the 1st busiest of the twelve months, out of 12 months with recorded activity.

Activity is rising from March (10.6%) into April, and it heads toward May (14.7%) after. This is right inside the peak window, so April 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 April split, so treat them as which species you are likely to encounter, while the month figures above show how many sightings fall in April 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 tripLewis & Clark National Historic Trail

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.

Frequently asked questions

Can you see tree frogs in Illinois in April?+

Yes. April accounts for 1,636 of the 8,972 verified tree frogs sightings logged in Illinois across the year, which is 18.2% of the annual total.

Is April a good time to see tree frogs in Illinois?+

April is one of the best months. It ranks 1st 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.