FleaDatesFlea seasonMassachusetts › Boston

Boston · MA

When does flea season start in Boston?

Flea season in Boston typically runs mid-April to early November, peaking May–Sep.

Flea season mid-April to early November Peak May–Sep
January — Quiet February — Quiet March — Quiet April — Low May — High June — Peak July — Peak August — Peak September — Peak October — Moderate November — Low December — Quiet J F M A M J J A S O N D Boston Peak May–Sep

Ticks in Boston

Local tick activity typically runs mid-March to early December, heaviest May–Oct. The species to know in Massachusetts: blacklegged (deer) tick, American dog tick, lone star tick.

More on species and timing: Massachusetts tick season.

Numbers come from NOAA U.S. Climate Normals (1991–2020) recorded at BOSTON LOGAN INTL AP — a climate-based estimate; real years wobble.

Frequently asked questions

When does flea season start in Boston?

Around mid-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 Boston different from the rest of Massachusetts?

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

Do dogs in Boston 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 Massachusetts are typically active mid-March to late November, a longer window than fleas get.

Elsewhere in Massachusetts