Best Time to See Monarch Butterflies in Idaho
August, September and July is the best time to see monarch butterflies in Idaho. Based on 481 verified iNaturalist observations, here is exactly when monarch butterflies are most active across the year in Idaho.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 28, 2026.
481 verified observations of monarch butterflies in Idaho, recorded across 6 months of the year on iNaturalist.
When monarch butterflies are recorded in Idaho
Peak month
August
172 records (35.8% of the year)
| Month | Observations | Share |
|---|---|---|
| January | 0 | 0% |
| February | 0 | 0% |
| March | 0 | 0% |
| April | 0 | 0% |
| May | 5 | 1% |
| June | 76 | 15.8% |
| Julypeak | 104 | 21.6% |
| Augustpeak | 172 | 35.8% |
| Septemberpeak | 105 | 21.8% |
| October | 19 | 4% |
| November | 0 | 0% |
| December | 0 | 0% |
Monarch Butterflies you are most likely to see
| Species | Verified observations |
|---|---|
| Monarch | 481 |
Weather to expect, source Open-Meteo
Typical weather in Idaho
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 43 to 82 degrees Fahrenheit, so pack for that.
| Month | Avg high | Avg low | Rain |
|---|---|---|---|
| Jan | 31°F | 13°F | 1.6" |
| Feb | 32°F | 14°F | 2.4" |
| Mar | 41°F | 20°F | 1.7" |
| Apr | 48°F | 25°F | 1.9" |
| May | 60°F | 35°F | 2.9" |
| Jun | 71°F | 44°F | 2.9" |
| Julbest time | 82°F | 51°F | 1.2" |
| Augbest time | 81°F | 51°F | 1.9" |
| Sepbest time | 71°F | 43°F | 1.9" |
| Oct | 54°F | 29°F | 1.8" |
| Nov | 40°F | 19°F | 1.8" |
| Dec | 31°F | 13°F | 1.8" |
Typical recent conditions (5-year means) from the Open-Meteo archive, averaged for Idaho. Weather varies year to year, so treat these as a guide.
More on monarch butterflies in Idaho:
Sightings of monarch butterflies in Idaho peak in August, when 172 of the year's 481 verified observations are logged — about 35.8% of the annual total. Activity stays high through August, September and July.
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 Idaho 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 Idaho
- City Of Rocks National Reserve — National Reserve
- Craters Of The Moon National Monument & Preserve — National Monument & Preserve
- Hagerman Fossil Beds National Monument — National Monument
- 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 Idaho?+
August is the single best month, and the broader peak window runs through August, September and July, based on 481 verified iNaturalist observations.
When are monarch butterflies hardest to see in Idaho?+
January is the quietest month for monarch butterflies in Idaho, with no verified records on iNaturalist.
Are monarch butterflies active year-round in Idaho?+
Monarch butterflies are recorded in 6 of 12 months in Idaho, concentrated around August and September.
More places to see monarch butterflies
More wildlife in Idaho