The Honolulu year in pollen

Pollen seasons in Honolulu: tree pollen March to October, grass January to December, and ragweed from early August, fading out by late December.

Tree pollen
Grass
Ragweed

When does ragweed season end in Honolulu?

Ragweed around Honolulu winds down on its own through late December — most winters never bring a season-ending freeze.

The rest of the Honolulu pollen year

AllergenTypical season
Kiawe (mesquite) March to October
Grass January to December

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

Nearby calendars

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