Best Time to See Cottonmouths in Missouri
April, May and August is the best time to see cottonmouths in Missouri. Based on 170 verified iNaturalist observations, here is exactly when cottonmouths 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 July 22, 2026.
Northern Cottonmouth · kirk gardner CC BY
Northern Cottonmouth · Mila Turov CC BY
Northern Cottonmouth · Joshua Liverman CC BY
170 verified observations of cottonmouths in Missouri, recorded across 9 months of the year on iNaturalist.
When cottonmouths are recorded in Missouri
Peak month
April
41 records (24.1% of the year)
| Month | Observations | Share |
|---|---|---|
| January | 0 | 0% |
| February | 0 | 0% |
| March | 11 | 6.5% |
| Aprilpeak | 41 | 24.1% |
| Maypeak | 35 | 20.6% |
| June | 16 | 9.4% |
| July | 10 | 5.9% |
| Augustpeak | 25 | 14.7% |
| September | 14 | 8.2% |
| October | 16 | 9.4% |
| November | 2 | 1.2% |
| December | 0 | 0% |
Cottonmouths you are most likely to see
| Species | Verified observations |
|---|---|
| Northern Cottonmouth | 170 |
Weather to expect, source Open-Meteo
Typical weather in Missouri
Recent typical conditions by month, so you can plan a trip around both when cottonmouths are active and what the weather is doing. The best months to look for cottonmouths sit around 45 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" |
| Aprbest time | 67°F | 45°F | 4.7" |
| Maybest time | 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" |
| Sep | 84°F | 63°F | 2.2" |
| Oct | 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.
Sightings of cottonmouths in Missouri peak in April, when 41 of the year's 170 verified observations are logged — about 24.1% of the annual total. Activity stays high through April, May and August.
The quietest stretch is January, February and December, when cottonmouths 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 cottonmouths you are most likely to encounter in Missouri are Northern Cottonmouth — 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 cottonmouths 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 cottonmouths in Missouri?+
April is the single best month, and the broader peak window runs through April, May and August, based on 170 verified iNaturalist observations.
When are cottonmouths hardest to see in Missouri?+
January is the quietest month for cottonmouths in Missouri, with no verified records on iNaturalist.
Are cottonmouths active year-round in Missouri?+
Cottonmouths are recorded in 9 of 12 months in Missouri, concentrated around April and May.
More places to see cottonmouths
More wildlife in Missouri