The Pocatello year in pollen
Pollen seasons in Pocatello: tree pollen March to June, grass May to July, and ragweed from early August until the first frost, around September 18.
Tree pollen
Grass
Ragweed
When does ragweed season end in Pocatello?
Ragweed season in Pocatello typically ends with the first frost, around September 18. Some years it comes as early as September 12, some as late as September 25.
A light frost around September 18 knocks the season down; the hard freeze that finishes it usually follows by October 1. Based on 30 years of NOAA frost records (1991–2020).
The rest of the Pocatello pollen year
| Allergen | Typical season |
|---|---|
| Juniper | March to May |
| Cottonwood and aspen | March to May |
| Maple (boxelder) | March to May |
| Birch and alder | April to May |
| Pine | May to June |
| Grass | May to July |
Season-by-season detail is on the Idaho page.
Nearby calendars
Frost dates for Pocatello come from the Pocatello Regional Airport weather station's 30-year records. Season windows reviewed August 2026.