Connecticut pollen and allergy seasons

September outlookVery high

Connecticut has a spring tree season and a strong ragweed season in late summer and early fall.

Twelve month pollen calendar

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LowModerateHighVery high
Dominant species in September
Ragweed
Typical peak in September
early-September to late-September
Worst month of the year
September
Best month of the year
January

What is active in September

Ragweed
Very high
Mugwort
Moderate

Cities in Connecticut

No tracked cities yet for Connecticut.

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 Connecticut for ozone, dust, and smoke readings by city.

The Connecticut allergy season

Allergy levels in Connecticut peak in September, when ragweed pollen runs highest. The season moves through tree pollen around April, grass in June, weed pollen such as ragweed in September. Levels start to climb around March. The lowest pollen levels of the year arrive in January.

Common questions

When does allergy season start in Connecticut?

Pollen levels in Connecticut usually begin climbing in March and reach their highest point in September.

What is the worst month for allergies in Connecticut?

September is typically the worst month in Connecticut, driven by ragweed pollen.

When does ragweed season end in Connecticut?

Ragweed pollen in Connecticut usually fades by the end of October, after the first hard frost in colder areas.

When is the best time for allergies in Connecticut?

January usually brings the lowest pollen levels of the year in Connecticut.