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Sioux City · IA

When does flea season start in Sioux City?

Flea season in Sioux City typically runs mid-April to late October, peaking May–Sep.

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

Ticks in Sioux City

Local tick activity typically runs mid-March to mid-November, heaviest May–Sep. The species to know in Iowa: American dog tick, blacklegged (deer) tick, lone star tick.

More on species and timing: Iowa tick season.

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

Frequently asked questions

When does flea season start in Sioux City?

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 Sioux City different from the rest of Iowa?

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

Do dogs in Sioux City 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 Iowa are typically active mid-March to mid-November, a longer window than fleas get.

Elsewhere in Iowa