FleaDates › Tick season › Ohio
Midwest · OH
When are ticks active in Ohio?
Ticks in Ohio are typically active early March to early December, heaviest May–Oct — and adult blacklegged ticks can surface on any mild winter day.
Ticks to know in Ohio
The blacklegged (deer) tick has expanded quickly across eastern and southern Ohio woodlands and now drives most of the Lyme concern here, alongside American dog ticks in grassy openings and lone star ticks in the southern counties. Pressure climbs through March and April, sits at its highest from May through September, and remains substantial in October — a mild early-December day can still produce an adult tick on a dog.
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 Ohio
| Month | Typical activity | Average temperature |
|---|---|---|
| January | Quiet | 29.5°F |
| February | Quiet | 31.9°F |
| March | Moderate | 40.4°F |
| April | Moderate | 51.7°F |
| May | Peak | 62.2°F |
| June | Peak | 71.1°F |
| July | Peak | 75°F |
| August | Peak | 73.6°F |
| September | Peak | 66.7°F |
| October | High | 55.2°F |
| November | Moderate | 43.6°F |
| December | Low | 34.4°F |
Estimates from NOAA U.S. Climate Normals (1991–2020), averaged across 4 weather stations near Ohio'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. Ohio flea season typically runs early April to early November — see the Ohio flea season page.
Frequently asked questions
When does tick season start in Ohio?
Around early March 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 Ohio?
The species dog owners most often meet in Ohio: blacklegged (deer) tick, American dog tick, lone star tick. The blacklegged (deer) tick has expanded quickly across eastern and southern Ohio woodlands and now drives most of the Lyme concern here, alongside American dog ticks in grassy openings and lone star ticks in the southern counties. Pressure climbs through March and April, sits at its highest from May through September, and remains substantial in October — a mild early-December day can still produce an adult tick on a dog.
Do I need tick prevention in winter in Ohio?
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 Ohio?
Fleas run on a warmer calendar — in Ohio that's early April to early November. See the Ohio flea season page for that month-by-month picture.