The Greensboro year in pollen

Pollen seasons in Greensboro: tree pollen January to May, grass April to September, and ragweed from early August until the first frost, around November 5.

Tree pollen
Grass
Ragweed
Ragweed's bar ends at the typical first frost — around November 5.

When does ragweed season end in Greensboro?

Ragweed season in Greensboro typically ends with the first frost, around November 5. Some years it comes as early as November 1, some as late as November 11.

A light frost around November 5 knocks the season down; the hard freeze that finishes it usually follows by November 17. Based on 30 years of NOAA frost records (1991–2020).

The rest of the Greensboro pollen year

AllergenTypical season
Oak March to May
Pine March to May
Eastern red cedar January to March
Maple February to April
Birch March to April
Hickory April to May
Grass April to September

Season-by-season detail is on the North Carolina page.

Nearby calendars

Frost dates for Greensboro come from the Piedmont Triad International Airport weather station's 30-year records. Season windows reviewed August 2026.