FleaDates › Tick season › Missouri
Midwest · MO
When are ticks active in Missouri?
Ticks in Missouri are typically active mid-February to early December, heaviest Apr–Oct — and adult blacklegged ticks can surface on any mild winter day.
Ticks to know in Missouri
Few states are as lone star tick-heavy as Missouri, and those fast-moving ticks account for much of what owners pull off dogs here; American dog ticks are common along grassy edges, and blacklegged (deer) ticks have been spreading through northern and eastern woodlands. The strongest run is May through September, with activity possible as early as February and lingering into early December. Ozark and river-bluff woods carry noticeably more tick pressure than open farmland, so give those walks a thorough check afterward.
Wherever the calendar sits this month, the habit that actually catches ticks is the after-walk check: ears, collar line, armpits, between the toes. Prevention plus checks beats either alone.
Month-by-month tick activity in Missouri
| Month | Typical activity | Average temperature |
|---|---|---|
| January | Quiet | 31.5°F |
| February | Low | 36°F |
| March | Moderate | 46°F |
| April | High | 56.1°F |
| May | Peak | 65.6°F |
| June | Peak | 74.6°F |
| July | Peak | 78.7°F |
| August | Peak | 77.3°F |
| September | Peak | 69.2°F |
| October | High | 57.5°F |
| November | Moderate | 45.2°F |
| December | Low | 35.4°F |
Estimates from NOAA U.S. Climate Normals (1991–2020), averaged across 4 weather stations near Missouri's larger cities, using the ~40°F activity threshold reported in published tick research. Real years run early or late with the weather.
Fleas peak later. Missouri flea season typically runs late March to mid-November — see the Missouri flea season page.
Frequently asked questions
When does tick season start in Missouri?
Around mid-February in a typical year, once temperatures clear roughly 40°F — noticeably earlier than flea season. A February thaw can bring ticks out ahead of schedule.
What ticks live in Missouri?
The species dog owners most often meet in Missouri: lone star tick, American dog tick, blacklegged (deer) tick. Few states are as lone star tick-heavy as Missouri, and those fast-moving ticks account for much of what owners pull off dogs here; American dog ticks are common along grassy edges, and blacklegged (deer) ticks have been spreading through northern and eastern woodlands. The strongest run is May through September, with activity possible as early as February and lingering into early December. Ozark and river-bluff woods carry noticeably more tick pressure than open farmland, so give those walks a thorough check afterward.
Do I need tick prevention in winter in Missouri?
Yes. Ticks overwinter under leaf litter and snow rather than dying off, and mild spells wake them — which is why veterinary organizations recommend year-round parasite prevention. The calendar shows when pressure peaks, not when protection can lapse.
What about fleas in Missouri?
Fleas run on a warmer calendar — in Missouri that's late March to mid-November. See the Missouri flea season page for that month-by-month picture.