The Tucson year in pollen
Pollen seasons in Tucson: tree pollen February to June, grass April to October, and ragweed from early August until the first frost, around December 9.
Tree pollen
Grass
Ragweed
When does ragweed season end in Tucson?
Ragweed season in Tucson typically ends with the first frost, around December 9. Some years it comes as early as November 30, some as late as December 17.
A light frost around December 9 knocks the season down; the hard freeze that finishes it usually follows by December 26. Based on 30 years of NOAA frost records (1991–2020).
The rest of the Tucson pollen year
| Allergen | Typical season |
|---|---|
| Juniper | February to April |
| Mulberry | February to April |
| Ash | February to April |
| Olive | April to May |
| Mesquite | April to June |
| Grass | April to October |
Season-by-season detail is on the Arizona page.
Nearby calendars
Frost dates for Tucson come from the Tucson International Airport weather station's 30-year records. Season windows reviewed August 2026.