FleaDates › Flea season › Montana › Great Falls
Great Falls · MT
When does flea season start in Great Falls?
Flea season in Great Falls typically runs early May to early October, peaking Jun–Aug.
Ticks in Great Falls
Local tick activity typically runs late March to early November, heaviest Jun–Sep. The species to know in Montana: Rocky Mountain wood tick, American dog tick, brown dog tick.
More on species and timing: Montana tick season.
Numbers come from NOAA U.S. Climate Normals (1991–2020) recorded at GREAT FALLS INTL AP — a climate-based estimate; real years wobble.
Frequently asked questions
When does flea season start in Great Falls?
Around early May in a typical year, once local averages hold around 50°F. A warm spring pulls it earlier — prevention shouldn't wait for the calendar.
Is flea season in Great Falls different from the rest of Montana?
Not meaningfully — Great Falls tracks the Montana statewide estimate closely. Both are climate-based estimates, so treat the edges as fuzzy, not exact.
Do dogs in Great Falls need prevention outside flea season?
Yes — vets recommend year-round parasite prevention regardless of the local calendar. Indoor fleas ignore the weather entirely, and ticks in Montana are typically active late March to early November, a longer window than fleas get.