FleaDatesFlea seasonMontana › Missoula

Missoula · MT

When does flea season start in Missoula?

Flea season in Missoula typically runs late April to early October, peaking Jun–Aug.

Flea season late April to early October Peak Jun–Aug
January — Quiet February — Quiet March — Quiet April — Low May — Moderate June — High July — Peak August — Peak September — Moderate October — Low November — Quiet December — Quiet J F M A M J J A S O N D Missoula Peak Jun–Aug

Ticks in Missoula

Local tick activity typically runs late March to early November, heaviest May–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 MISSOULA INTL AP — a climate-based estimate; real years wobble.

Frequently asked questions

When does flea season start in Missoula?

Around late April 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 Missoula different from the rest of Montana?

Not meaningfully — Missoula tracks the Montana statewide estimate closely. Both are climate-based estimates, so treat the edges as fuzzy, not exact.

Do dogs in Missoula 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.

Elsewhere in Montana