The Brownsville year in pollen

Pollen seasons in Brownsville: tree pollen December to May, grass March to October, and ragweed from early August until the first frost, around January 2.

First frost lands around January 2 in Brownsville — about 34 days later than Texas overall — which shifts when ragweed season ends here.

Tree pollen
Grass
Ragweed
Ragweed's bar ends at the typical first frost — around January 2.

When does ragweed season end in Brownsville?

Ragweed season in Brownsville typically ends with the first frost, around January 2. Some years it comes as early as December 24, some as late as January 9.

The rest of the Brownsville pollen year

AllergenTypical season
Mountain cedar (Ashe juniper) December to February
Oak (live oak) March to May
Elm February to April
Cedar elm (fall) August to October
Pecan April to May
Cottonwood March to April
Grass March to October

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

Nearby calendars

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