The Madison year in pollen
Pollen seasons in Madison: tree pollen March to June, grass May to July, and ragweed from mid-August until the first frost, around October 10.
Tree pollen
Grass
Ragweed
When does ragweed season end in Madison?
Ragweed season in Madison typically ends with the first frost, around October 10. Some years it comes as early as October 4, some as late as October 15.
A light frost around October 10 knocks the season down; the hard freeze that finishes it usually follows by October 22. Based on 30 years of NOAA frost records (1991–2020).
The rest of the Madison 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 Wisconsin page.
Nearby calendars
Frost dates for Madison come from the Madison Dane Regional Airport weather station's 30-year records. Season windows reviewed August 2026.