Bats in Wisconsin in September
Yes, September is one of the best months to see bats in Wisconsin. It is the 3rd busiest month of the year, with 62 of the 546 sightings logged across the year (11.4%), based on verified iNaturalist records.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 28, 2026.
Peak month for bats in Wisconsin
11.4%
of yearly sightings
62
records in September
#3
busiest month of 12
546
verified records a year
August 21.2%, September 11.4%, October 11%. Busiest month is August at 21.2%.
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)
| Month | Observations | Share |
|---|---|---|
| January | 10 | 1.8% |
| February | 9 | 1.6% |
| March | 23 | 4.2% |
| April | 42 | 7.7% |
| May | 59 | 10.8% |
| June | 61 | 11.2% |
| Julypeak | 72 | 13.2% |
| Augustpeak | 116 | 21.2% |
| Septemberpeak | 62 | 11.4% |
| October | 60 | 11% |
| November | 19 | 3.5% |
| December | 13 | 2.4% |
Bats you are most likely to see
| Species | Verified observations |
|---|---|
| Big Brown Bat | 212 |
| Silver-haired Bat | 50 |
| Eastern Red Bat | 49 |
| Little Brown Bat | 48 |
| Northern Hoary Bat | 15 |
| Tri-coloured Bat | 10 |
| Northern Myotis | 1 |
In Wisconsin, September carries 11.4% of the year's bats sightings, about 3.1 points above an even month-to-month split. That makes it the 3rd busiest of the twelve months, out of 12 months with recorded activity.
Activity is easing off from August (21.2%) into September, and it heads toward October (11%) after. This is right inside the peak window, so September is one of the surest months to plan a trip around.
The bats most often recorded in Wisconsin are Big Brown Bat, Silver-haired Bat and Eastern Red Bat. Those counts are annual totals rather than a September split, so treat them as which species you are likely to encounter, while the month figures above show how many sightings fall in September itself.
Which bats you are most likely to see
- Big Brown Bat212 records
- Silver-haired Bat50 records
- Eastern Red Bat49 records
- Little Brown Bat48 records
- Northern Hoary Bat15 records
- Tri-coloured Bat10 records
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.
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Live tours nearbySee live tours near Apostle Islands National Lakeshore
Use the live GetYourGuide widget to compare local departures and activity styles close to the main bat viewing area.
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Compare guided wildlife tours, boat trips and nature experiences if you want a second travel network beyond the live widget.
Gear to see them
Frequently asked questions
Can you see bats in Wisconsin in September?+
Yes. September accounts for 62 of the 546 verified bats sightings logged in Wisconsin across the year, which is 11.4% of the annual total.
Is September a good time to see bats in Wisconsin?+
September is one of the best months. It ranks 3rd of the year and sits inside the peak window of August, July and September.
What month is best for bats in Wisconsin?+
August is the single busiest month, with the broader peak running through August, July and September, based on 546 verified observations.
Which bats are you most likely to see in Wisconsin?+
The most-recorded species in Wisconsin are Big Brown Bat, Silver-haired Bat and Eastern Red Bat, based on all-time iNaturalist counts.
See bats in Wisconsin in other months
More places to see bats
More wildlife in Wisconsin