The Hagerstown year in pollen
Pollen seasons in Hagerstown: tree pollen March to June, grass May to July, and ragweed from early August until the first frost, around November 4.
Tree pollen
Grass
Ragweed
When does ragweed season end in Hagerstown?
Ragweed season in Hagerstown typically ends with the first frost, around November 4. Some years it comes as early as October 29, some as late as November 8.
A light frost around November 4 knocks the season down; the hard freeze that finishes it usually follows by November 14. Based on 30 years of NOAA frost records (1991–2020).
The rest of the Hagerstown pollen year
| Allergen | Typical season |
|---|---|
| Oak | March to May |
| Maple | March to April |
| Birch | March to May |
| Ash | March to April |
| Pine | April to June |
| Grass | May to July |
Season-by-season detail is on the Maryland page.
Nearby calendars
Frost dates for Hagerstown come from the Hagerstown Washington Co Airport weather station's 30-year records. Season windows reviewed August 2026.