The North Carolina year in pollen
Tree pollen in North Carolina 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 4.
When does ragweed season end in North Carolina?
Ragweed season in North Carolina typically ends with the first frost, around November 4. The coldest corners of the state see frost by late October; the mildest hold out until mid-November.
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 North Carolina
Tree pollen in North Carolina 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 North Carolina 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 North Carolina over several weeks, and ragweed season ends with it. Based on 30 years of NOAA frost records (1991–2020).
| City | Typical first frost |
|---|---|
| Asheville | October 31 |
| Charlotte | November 3 |
| Durham | November 4 |
| Greensboro | November 5 |
| Raleigh | November 4 |
| Wilmington | November 20 |
| Winston-Salem | November 9 |
Common questions
When does ragweed season end in North Carolina?
Ragweed season in North Carolina typically ends with the first frost, around November 4. The coldest corners of the state see frost by late October; the mildest hold out until mid-November.
When does allergy season end in North Carolina?
The last big wave of the North Carolina pollen year is ragweed, so the season ends with the first frost, around November 4. Tree pollen is done by May, grass mostly by September.
When does tree pollen start in North Carolina?
Tree pollen in North Carolina 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.