Low
Pollen is low — most people won't notice
Grass pollen is the main trigger · Tomorrow → · Updated 13 hours ago
Today in San Francisco: grass pollen is very low, tree pollen is none, weed pollen is none. Overall score: 6/100. Allergies are unlikely for most people right now. Tomorrow is expected to be about the same. Updated at 11:01 PM.
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Pollen levels in San Francisco are currently low. Most people should not experience allergy symptoms from pollen.
Tree pollen: None. Grass pollen: Very Low. Weed pollen: None.
Tomorrow's pollen forecast for San Francisco is expected to be about the same, with low pollen conditions.
Grass pollen is the highest supported pollen type in San Francisco today. Grass pollen is very low.
Tree pollen in San Francisco is none today.
Grass pollen in San Francisco is very low today.
Weed pollen in San Francisco is none today.
Tomorrow's pollen forecast for San Francisco is expected to be about the same, with low pollen conditions.
The allergy forecast in San Francisco is low today based on the supported tree, grass, and weed pollen data shown on this page.
San Francisco's mild, maritime climate produces a relatively long but moderate allergy season, with cool, wet winters and dry summers shaping a year-round exposure pattern rather than sharp seasonal spikes.
Tree pollen is typically the first major trigger, emerging as early as January and peaking from February through April. Common culprits include oak, cypress, juniper, olive, walnut, alder, and the widely planted acacia and eucalyptus, both of which are notorious for producing heavy, irritating pollen loads across the Bay Area.
As trees taper off, grass pollen takes over from late April through July, dominated by Bermuda, rye, fescue, and Kentucky bluegrass, with windy afternoons often carrying pollen in from surrounding hillsides. The tail end of grass season frequently overlaps with early weed pollination, intensifying symptoms in late spring.
Weed pollen peaks from August through October, driven by ragweed (less severe here than inland), sagebrush, pigweed, lamb's quarters, and plantain.
Non-pollen allergens are also significant: coastal fog and damp housing stock encourage indoor mold, dust mites thrive in the humid microclimate, and traffic-related air pollution can amplify respiratory irritation.
Overall, San Francisco's allergy profile is defined by a prolonged, overlapping season of moderate pollen levels compounded by persistent mold and urban air quality issues.