The Morgantown year in pollen

Pollen seasons in Morgantown: tree pollen March to June, grass May to July, and ragweed from early August until the first frost, around October 24.

Tree pollen
Grass
Ragweed
Ragweed's bar ends at the typical first frost — around October 24.

When does ragweed season end in Morgantown?

Ragweed season in Morgantown typically ends with the first frost, around October 24. Some years it comes as early as October 18, some as late as October 29.

A light frost around October 24 knocks the season down; the hard freeze that finishes it usually follows by November 4. Based on 30 years of NOAA frost records (1991–2020).

The rest of the Morgantown pollen year

AllergenTypical 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 West Virginia page.

Nearby calendars

Frost dates for Morgantown come from the Morgantown Hart Field weather station's 30-year records. Season windows reviewed August 2026.