Otters in Illinois in December

Yes, December is a good month to see otters in Illinois. It is the 4th busiest month of the year, with 14 of the 128 sightings logged across the year (10.9%), 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.

Good month for otters in Illinois

10.9%

of yearly sightings

14

records in December

#4

busiest month of 12

128

verified records a year

November 4.7%, December 10.9%, January 5.5%. Busiest month is February at 12.5%.

Best months: February, March, June

128 verified observations of otters in Illinois, recorded across 12 months of the year on iNaturalist.

When otters are recorded in Illinois

Peak month

February

16 records (12.5% of the year)

Quietest month

November

6 records

MonthObservationsShare
January75.5%
Februarypeak1612.5%
Marchpeak1612.5%
April118.6%
May97%
Junepeak1511.7%
July86.3%
August75.5%
September107.8%
October97%
November64.7%
December1410.9%

Otters you are most likely to see

SpeciesVerified observations
North American River Otter128

In Illinois, December carries 10.9% of the year's otters sightings, about 2.6 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 is rising from November (4.7%) into December, and it heads toward January (5.5%) after. The busiest month is February (12.5%), so if timing is flexible, that window is the safer bet.

The otters most often recorded in Illinois are North American River Otter. Those counts are annual totals rather than a December split, so treat them as which species you are likely to encounter, while the month figures above show how many sightings fall in December itself.

Which otters you are most likely to see

  • North American River Otter128 records
Plan your tripLewis & Clark National Historic Trail

Plan your otter 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 otters in Illinois in December?+

Yes. December accounts for 14 of the 128 verified otters sightings logged in Illinois across the year, which is 10.9% of the annual total.

Is December a good time to see otters in Illinois?+

December is the 4th busiest month. It is workable, though February and March is the stronger window for a reliable sighting.

What month is best for otters in Illinois?+

February is the single busiest month, with the broader peak running through February, March and June, based on 128 verified observations.

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

The most-recorded species in Illinois are North American River Otter, based on all-time iNaturalist counts.