The Cleveland year in pollen
Pollen seasons in Cleveland: tree pollen February to May, grass May to July, and ragweed from early August until the first frost, around November 12.
First frost lands around November 12 in Cleveland — about 16 days later than Ohio overall — which shifts when ragweed season ends here.
When does ragweed season end in Cleveland?
Ragweed season in Cleveland typically ends with the first frost, around November 12. Some years it comes as early as November 7, some as late as November 18.
A light frost around November 12 knocks the season down; the hard freeze that finishes it usually follows by November 22. Based on 30 years of NOAA frost records (1991–2020).
The rest of the Cleveland pollen year
| Allergen | Typical season |
|---|---|
| Oak | April to May |
| Maple | March to April |
| Elm | February to April |
| Birch | April to May |
| Ash | April to May |
| Hickory and walnut | April to May |
| Grass | May to July |
Season-by-season detail is on the Ohio page.
Nearby calendars
Frost dates for Cleveland come from the Cleveland Burke Airport weather station's 30-year records. Season windows reviewed August 2026.