FleaDates › Tick season › Indiana
Midwest · IN
When are ticks active in Indiana?
Ticks in Indiana are typically active early March to early December, heaviest Apr–Oct — and adult blacklegged ticks can surface on any mild winter day.
Ticks to know in Indiana
American dog ticks are the ones most Hoosier dogs pick up along grassy field edges, blacklegged (deer) ticks are established in the northwestern lake counties and wooded ravines, and lone star ticks concentrate in the southern third of the state. The heavy stretch is May through September, but pressure is already real in April and doesn't fully taper until late fall — even early December can put a tick on a dog during a mild spell.
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 Indiana
| Month | Typical activity | Average temperature |
|---|---|---|
| January | Quiet | 29.3°F |
| February | Quiet | 32.9°F |
| March | Moderate | 42.6°F |
| April | High | 53.7°F |
| May | Peak | 64°F |
| June | Peak | 72.9°F |
| July | Peak | 76.1°F |
| August | Peak | 74.4°F |
| September | Peak | 67.6°F |
| October | High | 55.8°F |
| November | Moderate | 43.6°F |
| December | Low | 34°F |
Estimates from NOAA U.S. Climate Normals (1991–2020), averaged across 3 weather stations near Indiana'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. Indiana flea season typically runs late March to early November — see the Indiana flea season page.
Frequently asked questions
When does tick season start in Indiana?
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 Indiana?
The species dog owners most often meet in Indiana: American dog tick, blacklegged (deer) tick, lone star tick. American dog ticks are the ones most Hoosier dogs pick up along grassy field edges, blacklegged (deer) ticks are established in the northwestern lake counties and wooded ravines, and lone star ticks concentrate in the southern third of the state. The heavy stretch is May through September, but pressure is already real in April and doesn't fully taper until late fall — even early December can put a tick on a dog during a mild spell.
Do I need tick prevention in winter in Indiana?
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 Indiana?
Fleas run on a warmer calendar — in Indiana that's late March to early November. See the Indiana flea season page for that month-by-month picture.