Pollen Count & Forecast for Phoenix
About Pollen in Phoenix
Phoenix’s spring allergy season (February-May) is dominated by Mulberry and Olive pollen; Mulberry (Morus) common in Encanto and historic districts; Olive (Olea europaea) widespread across residential areas. Ash (Fraxinus) and Mountain Cedar (Juniperus) contribute significantly from the Salt River and surrounding hills. Summer and autumn (August-October) see high Ragweed (Ambrosia) and Bermuda Grass (Cynodon dactylon) pollen levels, originating in the Phoenix Mountains Preserve and along canal banks.
The Salt River Valley’s bowl shape traps particles during thermal inversions; dry desert winds carry dust from the Sonoran Desert. Year-round Mould (Alternaria, Cladosporium) counts rise during the summer monsoon; moisture in irrigated gardens and desert soil increases spore release.