Best Time to See Mountain Lions in Illinois

October is the best time to see mountain lions in Illinois. Based on 1 verified iNaturalist observations, here is exactly when mountain lions are most active across the year in Illinois.

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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.

Best months: October

1 verified observations of mountain lions in Illinois, recorded across 1 months of the year on iNaturalist.

When mountain lions are recorded in Illinois

Peak month

October

1 records (100% of the year)

Quietest month

January

No verified records

MonthObservationsShare
January00%
February00%
March00%
April00%
May00%
June00%
July00%
August00%
September00%
Octoberpeak1100%
November00%
December00%

Mountain Lions you are most likely to see

SpeciesVerified observations
Mountain Lion1

Weather to expect, source Open-Meteo

Typical weather in Illinois

Recent typical conditions by month, so you can plan a trip around both when mountain lions are active and what the weather is doing. The best months to look for mountain lions sit around 48 to 65 degrees Fahrenheit, so pack for that.

MonthAvg highAvg lowRain
Jan38°F23°F3"
Feb40°F22°F3.1"
Mar53°F34°F4.8"
Apr63°F43°F4.1"
May73°F54°F4.6"
Jun83°F64°F3.5"
Jul85°F68°F4.3"
Aug83°F66°F3.9"
Sep79°F61°F3"
Octbest time65°F48°F4.9"
Nov52°F35°F1.8"
Dec45°F29°F2.3"

Typical recent conditions (5-year means) from the Open-Meteo archive, averaged for Illinois. Weather varies year to year, so treat these as a guide.

Sightings of mountain lions in Illinois peak in October, when 1 of the year's 1 verified observations are logged — about 100% of the annual total.

The quietest stretch is January, February and March, when mountain lions are hardest to find — no verified records exist for January. If a reliable sighting matters, plan around the peak window rather than the off-season.

The mountain lions you are most likely to encounter in Illinois are Mountain Lion — 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 mountain lions in Illinois

  • Lewis & Clark National Historic TrailNational Historic Trail
  • Lincoln Home National Historic SiteNational Historic Site
  • Emmett Till and Mamie Till-Mobley National MonumentNational Monument
  • Mormon Pioneer National Historic TrailNational Historic Trail
  • New Philadelphia National Historic SiteNational Historic Site
  • Pullman National Historical ParkNational Historical Park

Frequently asked questions

What is the best month to see mountain lions in Illinois?+

October is the single best month, and the broader peak window runs through October, based on 1 verified iNaturalist observations.

When are mountain lions hardest to see in Illinois?+

January is the quietest month for mountain lions in Illinois, with no verified records on iNaturalist.

Are mountain lions active year-round in Illinois?+

Mountain lions are recorded in 1 of 12 months in Illinois, concentrated around October.