Best Time to See Monarch Butterflies in Washington
August, July and September is the best time to see monarch butterflies in Washington. Based on 131 verified iNaturalist observations, here is exactly when monarch butterflies 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.
Monarch · RJ Baltierra CC BY
131 verified observations of monarch butterflies in Washington, recorded across 8 months of the year on iNaturalist.
When monarch butterflies are recorded in Washington
Peak month
August
40 records (30.5% of the year)
| Month | Observations | Share |
|---|---|---|
| January | 0 | 0% |
| February | 0 | 0% |
| March | 0 | 0% |
| April | 2 | 1.5% |
| May | 1 | 0.8% |
| June | 6 | 4.6% |
| Julypeak | 37 | 28.2% |
| Augustpeak | 40 | 30.5% |
| Septemberpeak | 28 | 21.4% |
| October | 16 | 12.2% |
| November | 1 | 0.8% |
| December | 0 | 0% |
Monarch Butterflies you are most likely to see
| Species | Verified observations |
|---|---|
| Monarch | 131 |
Weather to expect, source Open-Meteo
Typical weather in Washington
Recent typical conditions by month, so you can plan a trip around both when monarch butterflies are active and what the weather is doing. The best months to look for monarch butterflies 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 monarch butterflies in Washington:
Sightings of monarch butterflies in Washington peak in August, when 40 of the year's 131 verified observations are logged — about 30.5% of the annual total. Activity stays high through August, July and September.
The quietest stretch is January, February and March, when monarch butterflies are hardest to find — no verified records exist for January. If a reliable sighting matters, plan around the peak window rather than the off-season.
The monarch butterflies you are most likely to encounter in Washington are Monarch — 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 monarch butterflies 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
Frequently asked questions
What is the best month to see monarch butterflies in Washington?+
August is the single best month, and the broader peak window runs through August, July and September, based on 131 verified iNaturalist observations.
When are monarch butterflies hardest to see in Washington?+
January is the quietest month for monarch butterflies in Washington, with no verified records on iNaturalist.
Are monarch butterflies active year-round in Washington?+
Monarch butterflies are recorded in 8 of 12 months in Washington, concentrated around August and July.
More places to see monarch butterflies
More wildlife in Washington