Toledo, OH Pollen Levels Today

Toledo, Ohio sits in the humid continental climate zone along the western edge of Lake Erie, a position that produces distinct allergy seasons shaped by lake-effect moisture, flat agricultural surroundings, and moderate winds that transport pollen across the region.

Tree pollen typically launches the allergy calendar from late March through May, with oak, maple, birch, ash, cottonwood, sycamore, and walnut among the dominant local contributors, peaking in April. As trees taper off, grass pollen takes over from mid-May through July, driven largely by timothy, Kentucky bluegrass, orchard grass, and ryegrass common to northwest Ohio's lawns, roadsides, and nearby farmland.

The transition period in late May and early June often brings overlapping tree and grass pollen, which can intensify symptoms for sensitized individuals.

Weed season follows from August into October, with ragweed as the primary offender alongside lamb's quarters, pigweed, and plantain, typically peaking in early to mid-September.

Beyond pollen, Toledo's lake-influenced humidity fuels persistent outdoor and indoor mold, particularly in spring and fall, while dust mites, agricultural particulates from surrounding farms, and occasional air quality dips add year-round challenges.

Overall, Toledo's allergy profile is defined by a long, layered pollen season amplified by humidity-driven mold and regional agricultural exposure.