Best Time to See Bats in Washington
August, July and September is the best time to see bats in Washington. Based on 953 verified iNaturalist observations, here is exactly when bats are most active across the year in Washington.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 28, 2026.
Silver-haired Bat · Jeff Bartlett CC BY
Townsend's Big-eared Bat · Josh Weaver CC BY
Big Brown Bat · Public domain CC0
953 verified observations of bats in Washington, recorded across 12 months of the year on iNaturalist.
When bats are recorded in Washington
Peak month
August
209 records (21.9% of the year)
| Month | Observations | Share |
|---|---|---|
| January | 25 | 2.6% |
| February | 29 | 3% |
| March | 58 | 6.1% |
| April | 85 | 8.9% |
| May | 95 | 10% |
| June | 111 | 11.6% |
| Julypeak | 138 | 14.5% |
| Augustpeak | 209 | 21.9% |
| Septemberpeak | 116 | 12.2% |
| October | 40 | 4.2% |
| November | 28 | 2.9% |
| December | 19 | 2% |
Bats you are most likely to see
| Species | Verified observations |
|---|---|
| Little Brown Bat | 77 |
| Silver-haired Bat | 70 |
| Big Brown Bat | 64 |
| Townsend's Big-eared Bat | 53 |
| California Myotis | 37 |
| Long-eared Myotis | 26 |
| Yuma Myotis | 15 |
| Northern Hoary Bat | 11 |
Weather to expect, source Open-Meteo
Typical weather in Washington
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 50 to 86 degrees Fahrenheit, so pack for that.
| Month | Avg high | Avg low | Rain |
|---|---|---|---|
| Jan | 35°F | 24°F | 4.5" |
| Feb | 36°F | 22°F | 2.8" |
| Mar | 46°F | 28°F | 1.2" |
| Apr | 56°F | 33°F | 1.3" |
| May | 67°F | 44°F | 1.2" |
| Jun | 76°F | 51°F | 0.9" |
| Julbest time | 86°F | 57°F | 0.2" |
| Augbest time | 86°F | 58°F | 0.3" |
| Sepbest time | 74°F | 50°F | 1.1" |
| Oct | 59°F | 39°F | 1.7" |
| Nov | 42°F | 29°F | 3.6" |
| Dec | 33°F | 23°F | 3.6" |
Typical recent conditions (5-year means) from the Open-Meteo archive, averaged for Washington. Weather varies year to year, so treat these as a guide.
More on bats in Washington:
Sightings of bats in Washington peak in August, when 209 of the year's 953 verified observations are logged — about 21.9% of the annual total. Activity stays high through August, July and September.
The quietest stretch is December, January and November, when bats are hardest to find — December sees just 19 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 Washington are Little Brown Bat, Silver-haired Bat and Big Brown 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 Washington
- Ebey's Landing National Historical Reserve — National Historical Reserve
- Fort Vancouver National Historic Site — National Historic Site
- Lewis & Clark National Historic Trail — National Historic Trail
- Lewis and Clark National Historical Park — National Historical Park
- Mount Rainier National Park — National Park
- Nez Perce National Historical Park — National Historical Park
Gear to see them
Frequently asked questions
What is the best month to see bats in Washington?+
August is the single best month, and the broader peak window runs through August, July and September, based on 953 verified iNaturalist observations.
When are bats hardest to see in Washington?+
December is the quietest month for bats in Washington, with only 19 verified records.
Are bats active year-round in Washington?+
Bats are recorded in 12 of 12 months in Washington, so they can be seen year-round, with a clear peak in August.
More places to see bats
More wildlife in Washington