The Minneapolis year in pollen
Pollen seasons in Minneapolis: tree pollen March to June, grass May to July, and ragweed from mid-August until the first frost, around October 18.
First frost lands around October 18 in Minneapolis — about 17 days later than Minnesota overall — which shifts when ragweed season ends here.
When does ragweed season end in Minneapolis?
Ragweed season in Minneapolis typically ends with the first frost, around October 18. Some years it comes as early as October 11, some as late as October 23.
A light frost around October 18 knocks the season down; the hard freeze that finishes it usually follows by October 29. Based on 30 years of NOAA frost records (1991–2020).
The rest of the Minneapolis pollen year
| Allergen | Typical season |
|---|---|
| Birch | April to May |
| Oak | April to June |
| Maple | March to May |
| Alder | March to April |
| Ash | April to May |
| Pine | May to June |
| Grass | May to July |
Season-by-season detail is on the Minnesota page.
Nearby calendars
Frost dates for Minneapolis come from the Minneapolis/st Paul Airport weather station's 30-year records. Season windows reviewed August 2026.