Best Time to See Monarch Butterflies in Missouri
September, August and October is the best time to see monarch butterflies in Missouri. Based on 5,555 verified iNaturalist observations, here is exactly when monarch butterflies are most active across the year in Missouri.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated June 28, 2026.
5,555 verified observations of monarch butterflies in Missouri, recorded across 11 months of the year on iNaturalist.
When monarch butterflies are recorded in Missouri
Peak month
September
1,878 records (33.8% of the year)
| Month | Observations | Share |
|---|---|---|
| January | 2 | 0% |
| February | 0 | 0% |
| March | 3 | 0.1% |
| April | 138 | 2.5% |
| May | 351 | 6.3% |
| June | 434 | 7.8% |
| July | 463 | 8.3% |
| Augustpeak | 1,641 | 29.5% |
| Septemberpeak | 1,878 | 33.8% |
| Octoberpeak | 613 | 11% |
| November | 30 | 0.5% |
| December | 2 | 0% |
Monarch Butterflies you are most likely to see
| Species | Verified observations |
|---|---|
| Monarch | 5,555 |
Weather to expect, source Open-Meteo
Typical weather in Missouri
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 49 to 88 degrees Fahrenheit, so pack for that.
| Month | Avg high | Avg low | Rain |
|---|---|---|---|
| Jan | 43°F | 27°F | 3" |
| Feb | 45°F | 25°F | 3.2" |
| Mar | 57°F | 37°F | 5.6" |
| Apr | 67°F | 45°F | 4.7" |
| May | 74°F | 56°F | 5.9" |
| Jun | 86°F | 65°F | 4.3" |
| Jul | 90°F | 70°F | 4.2" |
| Augbest time | 88°F | 69°F | 5.1" |
| Sepbest time | 84°F | 63°F | 2.2" |
| Octbest time | 68°F | 49°F | 5" |
| Nov | 57°F | 38°F | 2.1" |
| Dec | 50°F | 32°F | 2.1" |
Typical recent conditions (5-year means) from the Open-Meteo archive, averaged for Missouri. Weather varies year to year, so treat these as a guide.
More on monarch butterflies in Missouri:
Sightings of monarch butterflies in Missouri peak in September, when 1,878 of the year's 5,555 verified observations are logged — about 33.8% of the annual total. Activity stays high through September, August and October.
The quietest stretch is February, when monarch butterflies are hardest to find — no verified records exist for February. 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 Missouri 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 Missouri
- George Washington Carver National Monument — National Monument
- Lewis & Clark National Historic Trail — National Historic Trail
- Ozark National Scenic Riverways — National Scenic Riverways
- Ulysses S Grant National Historic Site — National Historic Site
- Wilson's Creek National Battlefield — National Battlefield
- Butterfield Overland National Historic Trail — National Historic Trail
Frequently asked questions
What is the best month to see monarch butterflies in Missouri?+
September is the single best month, and the broader peak window runs through September, August and October, based on 5,555 verified iNaturalist observations.
When are monarch butterflies hardest to see in Missouri?+
February is the quietest month for monarch butterflies in Missouri, with no verified records on iNaturalist.
Are monarch butterflies active year-round in Missouri?+
Monarch butterflies are recorded in 11 of 12 months in Missouri, so they can be seen year-round, with a clear peak in September.
More places to see monarch butterflies
More wildlife in Missouri