The Baton Rouge year in pollen

Pollen seasons in Baton Rouge: tree pollen January to May, grass April to September, and ragweed from early August until the first frost, around November 26.

Tree pollen
Grass
Ragweed
Ragweed's bar ends at the typical first frost — around November 26.

When does ragweed season end in Baton Rouge?

Ragweed season in Baton Rouge typically ends with the first frost, around November 26. Some years it comes as early as November 17, some as late as December 3.

A light frost around November 26 knocks the season down; the hard freeze that finishes it usually follows by December 11. Based on 30 years of NOAA frost records (1991–2020).

The rest of the Baton Rouge pollen year

AllergenTypical season
Oak February to May
Pine February to April
Eastern red cedar January to March
Pecan April to May
Grass April to September

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

Nearby calendars

Frost dates for Baton Rouge come from the Baton Rouge Ryan Airport weather station's 30-year records. Season windows reviewed August 2026.