Pollen Count in Madison, WI

Madison, Wisconsin experiences a pronounced allergy season shaped by its humid continental climate, abundant surrounding woodlands, prairies, and proximity to lakes, all of which contribute to high pollen and mold loads from spring through fall.

Tree pollen typically launches the season in late March and peaks through April and May, driven by oak, maple, birch, elm, ash, cottonwood, and box elder—species that dominate Dane County's urban canopy and river corridors.

As tree pollen tapers, grass pollen rises from mid-May through July, with Kentucky bluegrass, timothy, orchard grass, and ryegrass being the primary culprits across Madison's lawns, parks, and rural fringes. The overlap between late-season trees and early grasses in May and June often intensifies symptoms for multi-sensitive sufferers.

Weed pollen takes over in August and persists through the first hard frost in October, with ragweed being the dominant trigger, alongside lamb's quarters, pigweed, and sagebrush.

Beyond pollen, Madison's humidity, frequent summer storms, and heavy leaf litter fuel persistent outdoor mold spores (notably Alternaria and Cladosporium), while cold, sealed winters elevate indoor dust mite exposure.

Overall, Madison's allergy profile is defined by a long, layered season with strong tree, ragweed, and mold components.