Tucson, AZ Pollen Levels Today

Tucson sits in the Sonoran Desert, and its warm, arid climate combined with a long growing season makes it one of the more challenging cities in the U.S. for allergy sufferers.

Tree pollen dominates from February through April, with mulberry, olive, ash, mesquite, juniper, cottonwood, and palo verde producing especially heavy loads—so much so that Pima County has long banned new plantings of mulberry and olive trees.

As temperatures climb, grass pollen takes over from late April through summer, with Bermuda grass as the primary offender alongside Johnson grass and various native desert grasses; Bermuda can linger well into fall given Tucson's mild climate.

Weed season intensifies in late summer and autumn, driven by the monsoon rains that fuel growth of ragweed, tumbleweed (Russian thistle), careless weed (amaranth/pigweed), and sagebrush, typically peaking from August through October. Overlap between lingering grasses and emerging weeds during the monsoon months often triggers compounded symptoms.

Non-pollen triggers are also significant: blowing dust from dry soils, outdoor molds that spike after monsoon storms, and particulate pollution can all aggravate allergies.

Overall, Tucson's allergy profile is defined by a nearly year-round pollen calendar, desert-specific plants, and dust and mold exacerbated by its dry, windy conditions.