The Omaha year in pollen

Pollen seasons in Omaha: tree pollen February to May, grass May to August, and ragweed from early August until the first frost, around October 21.

First frost lands around October 21 in Omaha — about 8 days later than Nebraska overall — which shifts when ragweed season ends here.

Tree pollen
Grass
Ragweed
Ragweed's bar ends at the typical first frost — around October 21.

When does ragweed season end in Omaha?

Ragweed season in Omaha typically ends with the first frost, around October 21. Some years it comes as early as October 15, some as late as October 26.

A light frost around October 21 knocks the season down; the hard freeze that finishes it usually follows by October 30. Based on 30 years of NOAA frost records (1991–2020).

The rest of the Omaha pollen year

AllergenTypical season
Eastern red cedar February to April
Elm February to April
Maple March to April
Oak April to May
Cottonwood April to May
Grass May to August

Season-by-season detail is on the Nebraska page.

Nearby calendars

Frost dates for Omaha come from the Omaha Eppley Airfield weather station's 30-year records. Season windows reviewed August 2026.