FleaDates › Flea season › Illinois › Springfield
Springfield · IL
When does flea season start in Springfield?
Flea season in Springfield typically runs late March to early November, peaking May–Sep.
Ticks in Springfield
Local tick activity typically runs late February to early December, heaviest Apr–Oct. The species to know in Illinois: blacklegged (deer) tick, American dog tick, lone star tick.
More on species and timing: Illinois tick season.
Numbers come from NOAA U.S. Climate Normals (1991–2020) recorded at SPRINGFIELD CAPITAL AP — a climate-based estimate; real years wobble.
Frequently asked questions
When does flea season start in Springfield?
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 Springfield different from the rest of Illinois?
Not meaningfully — Springfield tracks the Illinois statewide estimate closely. Both are climate-based estimates, so treat the edges as fuzzy, not exact.
Do dogs in Springfield 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 Illinois are typically active early March to late November, a longer window than fleas get.