The Alabama year in pollen
Tree pollen in Alabama runs January to May, grass follows April to September, and ragweed starts in early August and holds on until the first frost — typically around November 11.
When does ragweed season end in Alabama?
Ragweed season in Alabama typically ends with the first frost, around November 11. The coldest corners of the state see frost by early November; the mildest hold out until early December.
Ragweed keeps releasing pollen until a freeze kills the plants, which is why the season has no fixed end date — it ends when the cold arrives. More on how frost ends ragweed season.
Tree pollen in Alabama
Tree pollen in Alabama starts in mid-January, and eastern red cedar is usually first out. Oak — the bigger problem for most people — follows March to May. Mild springs pull the start earlier.
| Tree | Typical season | Heaviest weeks |
|---|---|---|
| Oak | March to May | late March to late April |
| Pine | March to May | mid-March to mid-April |
| Eastern red cedar | January to March | early February to early March |
| Maple | February to April | — |
| Birch | March to April | — |
| Hickory | April to May | — |
Grass season
Grass pollen in Alabama runs April to September, heaviest early May to late June. Cool-season grasses flower in the first wave; warm-season grasses like Bermuda pick up through summer, which stretches the season. More on grass seasons.
First frost — and ragweed's end — city by city
The first frost sweeps across Alabama over several weeks, and ragweed season ends with it. Based on 30 years of NOAA frost records (1991–2020).
| City | Typical first frost |
|---|---|
| Birmingham | November 11 |
| Huntsville | November 8 |
| Mobile | December 6 |
| Montgomery | November 13 |
Common questions
When does ragweed season end in Alabama?
Ragweed season in Alabama typically ends with the first frost, around November 11. The coldest corners of the state see frost by early November; the mildest hold out until early December.
When does allergy season end in Alabama?
The last big wave of the Alabama pollen year is ragweed, so the season ends with the first frost, around November 11. Tree pollen is done by May, grass mostly by September.
When does tree pollen start in Alabama?
Tree pollen in Alabama starts in mid-January, and eastern red cedar is usually first out. Oak — the bigger problem for most people — follows March to May. Mild springs pull the start earlier.
Sources: NOAA U.S. Climate Normals (1991–2020 frost records) · Asthma and Allergy Foundation of America — Ragweed Pollen. Season windows reviewed August 2026.