The South Bend year in pollen
Pollen seasons in South Bend: tree pollen February to May, grass May to July, and ragweed from early August until the first frost, around October 19.
Tree pollen
Grass
Ragweed
When does ragweed season end in South Bend?
Ragweed season in South Bend typically ends with the first frost, around October 19. Some years it comes as early as October 14, some as late as October 24.
A light frost around October 19 knocks the season down; the hard freeze that finishes it usually follows by October 31. Based on 30 years of NOAA frost records (1991–2020).
The rest of the South Bend 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 Indiana page.
Nearby calendars
Frost dates for South Bend come from the South Bend Michiana Regional Airport weather station's 30-year records. Season windows reviewed August 2026.