The Salt Lake City year in pollen
Pollen seasons in Salt Lake City: tree pollen March to June, grass May to July, and ragweed from early August until the first frost, around October 31.
First frost lands around October 31 in Salt Lake City — about 9 days later than Utah overall — which shifts when ragweed season ends here.
When does ragweed season end in Salt Lake City?
Ragweed season in Salt Lake City typically ends with the first frost, around October 31. Some years it comes as early as October 25, some as late as November 5.
A light frost around October 31 knocks the season down; the hard freeze that finishes it usually follows by November 10. Based on 30 years of NOAA frost records (1991–2020).
The rest of the Salt Lake City 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 Utah page.
Nearby calendars
Frost dates for Salt Lake City come from the Salt Lake City International Airport weather station's 30-year records. Season windows reviewed August 2026.