The Bangor year in pollen
Pollen seasons in Bangor: tree pollen March to June, grass May to July, and ragweed from mid-August until the first frost, around October 4.
Tree pollen
Grass
Ragweed
When does ragweed season end in Bangor?
Ragweed season in Bangor typically ends with the first frost, around October 4. Some years it comes as early as September 30, some as late as October 10.
A light frost around October 4 knocks the season down; the hard freeze that finishes it usually follows by October 17. Based on 30 years of NOAA frost records (1991–2020).
The rest of the Bangor pollen year
| Allergen | Typical season |
|---|---|
| Maple | March to April |
| Birch | April to May |
| Oak | April to June |
| Ash | April to May |
| Pine | May to June |
| Grass | May to July |
Season-by-season detail is on the Maine page.
Nearby calendars
Frost dates for Bangor come from the Bangor International Airport weather station's 30-year records. Season windows reviewed August 2026.