Arlington Heights, IL Pollen Levels Today

Arlington Heights, Illinois, sits in the humid continental climate of the Chicago metro area, giving residents a full spectrum of seasonal allergens driven by distinct springs, warm humid summers, and crisp falls.

Tree pollen kicks off the allergy calendar in late March and typically peaks from mid-April through May, with oak, maple, birch, ash, elm, cottonwood, and hickory among the dominant local contributors. As tree counts taper in late May, grass pollen takes over, running strong through June and into July, fueled largely by Kentucky bluegrass, timothy, orchard grass, and ryegrass common to suburban lawns and nearby prairie remnants. This tree-to-grass transition often creates a late-spring overlap that intensifies symptoms for many sufferers.

Weed pollen dominates the fall season, emerging in mid-August and peaking in September, with short ragweed the primary culprit—capable of traveling for miles—alongside lamb's quarters, pigweed, and sagebrush.

Beyond pollen, Arlington Heights' humid summers and heavy leaf litter promote outdoor mold spores (especially Alternaria and Cladosporium), while winter heating concentrates indoor dust mites. Proximity to Chicago-area traffic corridors also adds particulate pollution that can amplify reactions.

Overall, the area's allergy profile is defined by a long, layered season spanning tree, grass, weed, and mold exposures.