Idaho pollen and allergy seasons
Idaho has a spring tree season, heavy grass in early summer, and a sagebrush led weed season in late summer.
Twelve month pollen calendar
What is active in September
Cities in Idaho
No tracked cities yet for Idaho.
Today and worst today come from live readings where available. Typical shows the usual level for this month from the seasonal profile.
Pollen is only half of what's in the air. See today's air quality in Idaho for ozone, dust, and smoke readings by city.
The Idaho allergy season
Allergy levels in Idaho peak in June, when grass pollen runs highest. The season moves through tree pollen around March, grass in June, weed pollen such as ragweed in August. Levels start to climb around March. The lowest pollen levels of the year arrive in January.
Common questions
When does allergy season start in Idaho?
Pollen levels in Idaho usually begin climbing in March and reach their highest point in June.
What is the worst month for allergies in Idaho?
June is typically the worst month in Idaho, driven by grass pollen.
When does ragweed season end in Idaho?
Ragweed pollen in Idaho usually fades by the end of September, after the first hard frost in colder areas.
When is the best time for allergies in Idaho?
January usually brings the lowest pollen levels of the year in Idaho.