Aurora, IL Pollen Levels Today

Aurora, Illinois, sits in the humid continental climate zone of northeastern Illinois, where distinct seasons and the surrounding mix of prairie, woodland, and agricultural land create a prolonged and varied allergy calendar.

Tree pollen kicks off the season in late March and peaks through April and May, with oak, maple, birch, elm, cottonwood, ash, and walnut driving most symptoms—oak and maple in particular produce heavy local loads. As tree counts taper in late May, grass pollen takes over and remains elevated through June and into July, dominated by Kentucky bluegrass, timothy, orchard grass, and ryegrass, all common in the Fox Valley's lawns and open fields.

There is typically a two- to three-week overlap between late tree and early grass season that can amplify symptoms for sensitized individuals.

Weed pollen becomes the primary concern from August through the first hard frost in October, with short and giant ragweed leading the way, supplemented by lamb's quarters, pigweed, and sagebrush carried in from nearby farmland.

Beyond pollen, Aurora's humid summers and damp springs encourage outdoor and indoor mold growth, while dust mites and urban particulate pollution add year-round triggers.

Overall, Aurora's allergy profile is defined by a long, overlapping season with notably strong tree and ragweed peaks.