High
Expect noticeable allergy symptoms
Weed pollen is the main trigger · Tomorrow ↓ · Updated 14 hours ago
Today in San Antonio: weed pollen is very high, tree pollen is moderate, grass pollen is moderate. Overall score: 68/100. Allergies are bad right now for many people. Tomorrow is expected to be lower. Pollen is expected to ease on October 7. Updated at 1:00 AM.
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Weed pollen is high — symptoms likely
Wear a mask outdoors
Filters pollen particles when outside
Use a HEPA air purifier
Reduces indoor pollen levels
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Pollen levels in San Antonio are currently elevated. Most allergy sufferers may experience symptoms including sneezing, runny nose, and itchy eyes.
Tree pollen: Moderate. Grass pollen: Moderate. Weed pollen: Very High.
Tomorrow's pollen forecast for San Antonio is expected to be lower, with moderate pollen conditions.
Weed pollen is the highest supported pollen type in San Antonio today. Weed pollen is very high.
Tree pollen in San Antonio is moderate today.
Grass pollen in San Antonio is moderate today.
Weed pollen in San Antonio is very high today.
San Antonio sits at the edge of the Texas Hill Country, and its warm, humid subtropical climate combined with a long growing season makes it one of the most challenging allergy cities in the United States. The area is especially infamous for its winter "cedar fever" outbreak, when mountain cedar (Ashe juniper) releases massive pollen loads from mid-December through February.
As cedar subsides, a second tree wave takes over in spring, with oak, ash, elm, pecan, mulberry, and hackberry peaking from February through April; oak pollen in particular can blanket the city in yellow dust. Grass pollen follows, dominating from late April into summer and often lingering through early fall, driven largely by Bermuda, Johnson, and Timothy grasses.
Weed season arrives in late summer and fall, with ragweed leading the charge from August through October, alongside pigweed, careless weed, and sagebrush. Overlap is common—late-spring tree and grass pollen frequently coincide, intensifying symptoms.
Beyond pollen, San Antonio's humidity fuels year-round mold spores (especially Alternaria and Cladosporium), while dust, cedar elm debris, and occasional Saharan dust plumes add to the burden. Overall, the city's allergy profile is defined by its severe cedar season, diverse tree and weed exposure, and nearly year-round symptom potential.
Tomorrow's pollen forecast for San Antonio is expected to be lower, with moderate pollen conditions.
The allergy forecast in San Antonio is high today based on the supported tree, grass, and weed pollen data shown on this page.
This forecast tracks supported tree, grass, and weed pollen for San Antonio. Cedar can be part of local tree-pollen season, but this page does not show a separate cedar or mold count unless source data provides it.