Best Time to See Monarch Butterflies in Montana
August, July and September is the best time to see monarch butterflies in Montana. Based on 106 verified iNaturalist observations, here is exactly when monarch butterflies are most active across the year in Montana.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 28, 2026.
Monarch · Alex Day CC BY
106 verified observations of monarch butterflies in Montana, recorded across 6 months of the year on iNaturalist.
When monarch butterflies are recorded in Montana
Peak month
August
44 records (41.5% of the year)
| Month | Observations | Share |
|---|---|---|
| January | 0 | 0% |
| February | 0 | 0% |
| March | 0 | 0% |
| April | 2 | 1.9% |
| May | 0 | 0% |
| June | 8 | 7.5% |
| Julypeak | 39 | 36.8% |
| Augustpeak | 44 | 41.5% |
| Septemberpeak | 11 | 10.4% |
| October | 2 | 1.9% |
| November | 0 | 0% |
| December | 0 | 0% |
Monarch Butterflies you are most likely to see
| Species | Verified observations |
|---|---|
| Monarch | 106 |
Weather to expect, source Open-Meteo
Typical weather in Montana
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 46 to 75 degrees Fahrenheit, so pack for that.
| Month | Avg high | Avg low | Rain |
|---|---|---|---|
| Jan | 29°F | 17°F | 1" |
| Feb | 22°F | 9°F | 1.5" |
| Mar | 33°F | 18°F | 1.1" |
| Apr | 40°F | 24°F | 2.3" |
| May | 53°F | 36°F | 3.5" |
| Jun | 65°F | 47°F | 3.2" |
| Julbest time | 75°F | 55°F | 2" |
| Augbest time | 74°F | 54°F | 1.7" |
| Sepbest time | 65°F | 46°F | 2.1" |
| Oct | 46°F | 31°F | 2" |
| Nov | 36°F | 23°F | 1" |
| Dec | 30°F | 18°F | 1" |
Typical recent conditions (5-year means) from the Open-Meteo archive, averaged for Montana. Weather varies year to year, so treat these as a guide.
More on monarch butterflies in Montana:
Sightings of monarch butterflies in Montana peak in August, when 44 of the year's 106 verified observations are logged — about 41.5% 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 Montana 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 Montana
- Big Hole National Battlefield — National Battlefield
- Bighorn Canyon National Recreation Area — National Recreation Area
- Grant-Kohrs Ranch National Historic Site — National Historic Site
- Lewis & Clark National Historic Trail — National Historic Trail
- Nez Perce National Historical Park — National Historical Park
- Yellowstone National Park — National Park
Frequently asked questions
What is the best month to see monarch butterflies in Montana?+
August is the single best month, and the broader peak window runs through August, July and September, based on 106 verified iNaturalist observations.
When are monarch butterflies hardest to see in Montana?+
January is the quietest month for monarch butterflies in Montana, with no verified records on iNaturalist.
Are monarch butterflies active year-round in Montana?+
Monarch butterflies are recorded in 6 of 12 months in Montana, concentrated around August and July.
More places to see monarch butterflies
More wildlife in Montana