Chicago, IL Oak Pollen
Oak pollen in Chicago usually peaks around April, reaching High at its worst. Chicago's allergy year is a short, sharp spring and a long ragweed fall: maple and oak in spring, grass through early summer, and ragweed rolling in off the prairie in late summer.
Oak peaks in April and May across the Chicago area, the height of the tree season.
Oak in Chicago today
Monday, July 27, 2026
Oak pollen by month in Chicago
How oak usually runs across the year. The current month is outlined.
Managing oak season in Chicago
If oak is your trigger, start a daily antihistamine like cetirizine (Zyrtec) or loratadine (Claritin) a week or two before the April peak, rather than waiting for symptoms. Keep windows closed on high-count mornings, shower and change clothes after time outside, and run the AC on recirculate in the car.
When symptoms don't ease with over-the-counter medicine, an allergist in Illinois can test whether oak is really what you react to and talk through longer-term options like allergy shots.
Sources
More pollen in Chicago
- Chicago ragweed pollen — peaks September.
- Chicago grass pollen — peaks June.
- Chicago maple pollen — peaks March to April.
- Chicago pollen calendar — every allergen, month by month.
- Chicago pollen count today — live tree, grass, and weed levels with a 5-day forecast.
- Illinois pollen season — the statewide calendar and other cities.
Get Chicago pollen alerts
We send a free email whenever pollen is High or Very High in Chicago. No spam, no daily emails when pollen is low. Just a heads-up on the days that matter.
Sign up for free alertsSeasonal pattern based on Illinois pollen data and local sources. Today's reading updated daily. MyPollenPal