Best Time to See Bats in Wisconsin

August, July and September is the best time to see bats in Wisconsin. Based on 546 verified iNaturalist observations, here is exactly when bats are most active across the year in Wisconsin.

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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.

Eastern Red Bat photographed in WisconsinBig Brown Bat photographed in WisconsinBig Brown Bat photographed in Wisconsin
Photos by iNaturalist observers, used under Creative Commons.
Best months: August, July, SeptemberPeak season right now

546 verified observations of bats in Wisconsin, recorded across 12 months of the year on iNaturalist.

When bats are recorded in Wisconsin

Peak month

August

116 records (21.2% of the year)

Quietest month

February

9 records

MonthObservationsShare
January101.8%
February91.6%
March234.2%
April427.7%
May5910.8%
June6111.2%
Julypeak7213.2%
Augustpeak11621.2%
Septemberpeak6211.4%
October6011%
November193.5%
December132.4%

Bats you are most likely to see

SpeciesVerified observations
Big Brown Bat212
Silver-haired Bat50
Eastern Red Bat49
Little Brown Bat48
Northern Hoary Bat15
Tri-coloured Bat10
Northern Myotis1

Sightings of bats in Wisconsin peak in August, when 116 of the year's 546 verified observations are logged — about 21.2% of the annual total. Activity stays high through August, July and September.

The quietest stretch is February, January and December, when bats are hardest to find — February sees just 9 records. If a reliable sighting matters, plan around the peak window rather than the off-season.

The bats you are most likely to encounter in Wisconsin are Big Brown Bat, Silver-haired Bat and Eastern Red Bat — 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 bats in Wisconsin

  • Apostle Islands National Lakeshore — National Lakeshore
  • Ice Age National Scenic Trail — National Scenic Trail
  • North Country National Scenic Trail — National Scenic Trail
  • Saint Croix National Scenic Riverway — National Scenic Riverway
Plan your tripApostle Islands National Lakeshore

Plan your bat trip in Wisconsin

Start with live tours near Apostle Islands National Lakeshore, then compare a nearby stay and a broader wildlife backup before you lock in the trip.

Gear to see them

Frequently asked questions

What is the best month to see bats in Wisconsin?+

August is the single best month, and the broader peak window runs through August, July and September, based on 546 verified iNaturalist observations.

When are bats hardest to see in Wisconsin?+

February is the quietest month for bats in Wisconsin, with only 9 verified records.

Are bats active year-round in Wisconsin?+

Bats are recorded in 12 of 12 months in Wisconsin, so they can be seen year-round, with a clear peak in August.