Best Time to See Bats in Pennsylvania
August, July and June is the best time to see bats in Pennsylvania. Based on 1,334 verified iNaturalist observations, here is exactly when bats are most active across the year in Pennsylvania.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 28, 2026.
Northern Hoary Bat · Public domain CC0
Eastern Red Bat · Christina Moresi CC BY
Eastern Red Bat · Brandon McCracken CC BY
1,334 verified observations of bats in Pennsylvania, recorded across 12 months of the year on iNaturalist.
When bats are recorded in Pennsylvania
Peak month
August
213 records (16% of the year)
| Month | Observations | Share |
|---|---|---|
| January | 29 | 2.2% |
| February | 39 | 2.9% |
| March | 67 | 5% |
| April | 143 | 10.7% |
| May | 153 | 11.5% |
| Junepeak | 171 | 12.8% |
| Julypeak | 206 | 15.4% |
| Augustpeak | 213 | 16% |
| September | 109 | 8.2% |
| October | 109 | 8.2% |
| November | 63 | 4.7% |
| December | 32 | 2.4% |
Bats you are most likely to see
| Species | Verified observations |
|---|---|
| Big Brown Bat | 577 |
| Eastern Red Bat | 181 |
| Silver-haired Bat | 61 |
| Little Brown Bat | 51 |
| Tri-coloured Bat | 43 |
| Northern Hoary Bat | 21 |
| Northern Myotis | 13 |
| Eastern Small-footed Myotis | 9 |
Weather to expect, source Open-Meteo
Typical weather in Pennsylvania
Recent typical conditions by month, so you can plan a trip around both when bats are active and what the weather is doing. The best months to look for bats sit around 59 to 86 degrees Fahrenheit, so pack for that.
| Month | Avg high | Avg low | Rain |
|---|---|---|---|
| Jan | 38°F | 23°F | 3.1" |
| Feb | 41°F | 23°F | 3.6" |
| Mar | 50°F | 31°F | 3.3" |
| Apr | 60°F | 40°F | 4.1" |
| May | 70°F | 49°F | 4.1" |
| Junbest time | 79°F | 59°F | 3.9" |
| Julbest time | 86°F | 65°F | 3.2" |
| Augbest time | 84°F | 64°F | 4.3" |
| Sep | 75°F | 57°F | 3.9" |
| Oct | 64°F | 47°F | 4" |
| Nov | 51°F | 35°F | 2.4" |
| Dec | 43°F | 29°F | 4.3" |
Typical recent conditions (5-year means) from the Open-Meteo archive, averaged for Pennsylvania. Weather varies year to year, so treat these as a guide.
Sightings of bats in Pennsylvania peak in August, when 213 of the year's 1,334 verified observations are logged — about 16% of the annual total. Activity stays high through August, July and June.
The quietest stretch is January, December and February, when bats are hardest to find — January sees just 29 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 Pennsylvania are Big Brown Bat, Eastern Red Bat and Silver-haired 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 Pennsylvania
- Appalachian National Scenic Trail — National Scenic Trail
- Captain John Smith Chesapeake National Historic Trail — National Historic Trail
- Chesapeake Bay
- Delaware Water Gap National Recreation Area — National Recreation Area
- Fort Necessity National Battlefield — National Battlefield
- Friendship Hill National Historic Site — National Historic Site
Gear to see them
Frequently asked questions
What is the best month to see bats in Pennsylvania?+
August is the single best month, and the broader peak window runs through August, July and June, based on 1,334 verified iNaturalist observations.
When are bats hardest to see in Pennsylvania?+
January is the quietest month for bats in Pennsylvania, with only 29 verified records.
Are bats active year-round in Pennsylvania?+
Bats are recorded in 12 of 12 months in Pennsylvania, so they can be seen year-round, with a clear peak in August.
More places to see bats
More wildlife in Pennsylvania