Frogs in Illinois in October

Yes, October is a good month to see frogs in Illinois. It is the 7th busiest month of the year, with 2,366 of the 29,185 sightings logged across the year (8.1%), 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 IllinoisWood Frog photographed in IllinoisAmerican Bullfrog photographed in Illinois
Photos by iNaturalist observers, used under Creative Commons.

Good month for frogs in Illinois

8.1%

of yearly sightings

2,366

records in October

#7

busiest month of 12

29,185

verified records a year

September 10.7%, October 8.1%, November 0.9%. Busiest month is May at 18.3%.

Best months: May, June, April

29,185 verified observations of frogs in Illinois, recorded across 12 months of the year on iNaturalist.

When frogs are recorded in Illinois

Peak month

May

5,342 records (18.3% of the year)

Quietest month

January

53 records

MonthObservationsShare
January530.2%
February3031%
March1,8036.2%
Aprilpeak4,42115.1%
Maypeak5,34218.3%
Junepeak4,58415.7%
July3,59912.3%
August3,24711.1%
September3,13310.7%
October2,3668.1%
November2580.9%
December760.3%

Frogs you are most likely to see

SpeciesVerified observations
American Toad6,738
American Bullfrog4,770
Green Frog2,562
Blanchard's Cricket Frog2,560
Northern Leopard Frog1,676
Fowler's Toad1,318
Southern Leopard Frog1,237
Gray Treefrog1,134

In Illinois, October carries 8.1% of the year's frogs sightings, about 0.2 points below an even month-to-month split. That makes it the 7th busiest of the twelve months, out of 12 months with recorded activity.

Activity is easing off from September (10.7%) into October, and it heads toward November (0.9%) after. The busiest month is May (18.3%), so if timing is flexible, that window is the safer bet.

The frogs most often recorded in Illinois are American Toad, American Bullfrog and Green Frog. 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 frogs you are most likely to see

  • American Toad6,738 records
  • American Bullfrog4,770 records
  • Green Frog2,562 records
  • Blanchard's Cricket Frog2,560 records
  • Northern Leopard Frog1,676 records
  • Fowler's Toad1,318 records
Plan your tripLewis & Clark National Historic Trail

Plan your 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.

Gear to see them

Frequently asked questions

Can you see frogs in Illinois in October?+

Yes. October accounts for 2,366 of the 29,185 verified frogs sightings logged in Illinois across the year, which is 8.1% of the annual total.

Is October a good time to see frogs in Illinois?+

October is the 7th busiest month. It is workable, though May and June is the stronger window for a reliable sighting.

What month is best for frogs in Illinois?+

May is the single busiest month, with the broader peak running through May, June and April, based on 29,185 verified observations.

Which frogs are you most likely to see in Illinois?+

The most-recorded species in Illinois are American Toad, American Bullfrog and Green Frog, based on all-time iNaturalist counts.