Fresno, CA Pollen Levels Today

Fresno sits in the heart of California's San Joaquin Valley, a region widely recognized as one of the most challenging places in the country for allergy sufferers. The valley's hot, dry summers, mild wet winters, and bowl-like geography trap airborne particles, creating prolonged and intense pollen exposure nearly year-round.

Tree pollen kicks off the season early, often as soon as late January and peaking through March and April, with mulberry, oak, olive, ash, sycamore, elm, and cedar among the most prevalent local offenders. As trees wind down, grass pollen takes over from April through July, dominated by Bermuda, rye, orchard, and Timothy grasses, with Bermuda in particular lingering well into the warm months. Weed pollen follows in late summer and fall, driven by ragweed, pigweed, Russian thistle (tumbleweed), sagebrush, and lamb's quarters, typically peaking from August through October.

Overlap between late tree and early grass seasons in spring, and between grass and weed seasons in summer, can significantly intensify symptoms. Non-pollen triggers are also substantial: agricultural dust, year-round mold spores, wildfire smoke, and valley fever-causing spores from dry soils all contribute.

Overall, Fresno's allergy profile is defined by long seasons, high pollen counts, and compounding environmental irritants.