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Grand Junction · CO
When does flea season start in Grand Junction?
Flea season in Grand Junction typically runs late March to late October, peaking May–Sep. That's about 2 weeks earlier than the Colorado statewide estimate — city warmth and lower elevation add up.
Ticks in Grand Junction
Local tick activity typically runs late February to late November, heaviest May–Oct. The species to know in Colorado: Rocky Mountain wood tick, American dog tick, brown dog tick.
More on species and timing: Colorado tick season.
Numbers come from NOAA U.S. Climate Normals (1991–2020) recorded at GRAND JUNCTION WALKER FLD — a climate-based estimate; real years wobble.
Frequently asked questions
When does flea season start in Grand Junction?
Around late March 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 Grand Junction different from the rest of Colorado?
Somewhat. That's about 2 weeks earlier than the Colorado statewide estimate — city warmth and lower elevation add up. The statewide page averages several stations across Colorado; this page uses the normals recorded at GRAND JUNCTION WALKER FLD.
Do dogs in Grand Junction 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 Colorado are typically active late February to late November, a longer window than fleas get.