The Sacramento year in pollen

Pollen seasons in Sacramento: tree pollen January to June, grass March to July, and ragweed from early August until the first frost, around December 16.

Tree pollen
Grass
Ragweed
Ragweed's bar ends at the typical first frost — around December 16.

When does ragweed season end in Sacramento?

Ragweed season in Sacramento typically ends with the first frost, around December 16. Some years it comes as early as December 7, some as late as December 28.

A light frost around December 16 knocks the season down; the hard freeze that finishes it usually follows by December 25. Based on 30 years of NOAA frost records (1991–2020).

The rest of the Sacramento pollen year

AllergenTypical season
Oak March to May
Cypress and juniper January to March
Alder January to March
Olive April to June
Walnut April to May
Grass March to July

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

Nearby calendars

Frost dates for Sacramento come from the Sacramento 5 Ese weather station's 30-year records. Season windows reviewed August 2026.