San Marcos, TX Pollen Count Today

Live pollen forecast and air quality for San Marcos, Texas

šŸ“ San Marcos, TXToday Ā· Sep 20
8/10
Breathabilityā„¢ Score
Excellent breathing conditions for most plans today.
šŸŒ³Tree Pollen
None
šŸŒ±Grass Pollen
Low
šŸŒæWeed Pollen
Low
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Today's Pollen Levels in San Marcos

Grass pollen is slightly elevated at Low levels in San Marcos. Overall conditions are manageable for most people. With a Breathabilityā„¢ Score of 8, breathing conditions look good for most people.

How Today's Pollen May Affect You

Mild allergy sufferers
Most plans can stay the same today. Grass pollen is elevated and air quality is Good, so a quick rinse after time outside may help.
Moderate allergy sufferers
Conditions look manageable with routine precautions. Keep windows closed during peak pollen periods and shower after outdoor time.
Severe allergy sufferers
Even on a better day, keep your usual high-protection routine and avoid long exposure when pollen spikes.

5-Day Pollen Forecast

Pollen in San Marcos holds at Low every day through Wednesday.

Today
Sep 19
Overall: Low
Tree: None
Grass: Low
Weed: Low
Wind: 16 mph (may spread pollen)
Rain: 4%
Humidity: 57%
Sun
Sep 20
Overall: Low
Tree: None
Grass: Low
Weed: Low
Wind: 16 mph (may spread pollen)
Rain: 9%
Humidity: 55%
Mon
Sep 21
Overall: Low
Tree: None
Grass: Low
Weed: None
Wind: 16 mph (may spread pollen)
Rain: 9%
Humidity: 57%
Tue
Sep 22
Overall: Low
Tree: None
Grass: Low
Weed: None
Wind: 16 mph (may spread pollen)
Rain: 4%
Humidity: 55%
Wed
Sep 23
Overall: Low
Tree: None
Grass: Low
Weed: None
Wind: 12 mph
Rain: 21%
Humidity: 59%

Tree Pollen in San Marcos Today

Tree pollen in San Marcos is None today. Tree pollen season typically runs from early spring through late May, peaking when deciduous trees release their pollen. On low days like today, outdoor activities are generally comfortable for most allergy sufferers.

Species Breakdown

Alder0 grains/mĀ³
Birch0 grains/mĀ³
Hazel0 grains/mĀ³
Oak0 grains/mĀ³

Grass Pollen in San Marcos Today

Grass pollen in San Marcos is Low today, reaching 15.39 grains/mĀ³. Grass is currently elevated. People with grass pollen sensitivity may notice nasal congestion and itchy eyes, especially during outdoor activities.

Common Symptoms

  • Itchy nose and eyes
  • Sneezing fits
  • Nasal congestion
  • Watery eyes
  • Coughing or wheezing for sensitive people

Species Breakdown

Grass15.39 grains/mĀ³

Weed Pollen in San Marcos Today

Weed pollen in San Marcos is Low today, reaching 2.26 grains/mĀ³. Ragweed and Mugwort are the primary driver. Ragweed is the most common allergen in this category, and elevated levels can trigger persistent symptoms even in people who are only mildly sensitive.

Common Symptoms

  • Persistent sneezing
  • Runny nose
  • Itchy eyes and throat
  • Nasal congestion
  • Fatigue from prolonged exposure

Species Breakdown

Ragweed2.26 grains/mĀ³
Mugwort0 grains/mĀ³

Air Quality in San Marcos Today

šŸŒ¬ļø
Air Quality
Good
Good

Air Pollutant Breakdown

PM2.5Good
7 Āµg/mĀ³
Tiny particles smaller than 2.5 micrometers that can reach deep into your lungs and bloodstream. High levels can affect breathing and heart health.
PM10Good
9 Āµg/mĀ³
Larger particles up to 10 micrometers, like dust or pollen. They can irritate your airways and worsen allergies or asthma.
Ozone (O3)Good
64 Āµg/mĀ³
Elevated levels irritate airways and can worsen asthma symptoms.
Nitrogen Dioxide (NO2)Good
4.9 Āµg/mĀ³
A respiratory irritant from vehicle exhaust that can trigger inflammation in sensitive airways.
Sulfur Dioxide (SO2)Good
0.6 Āµg/mĀ³
Even brief exposure can tighten airways, especially for people with asthma.
Carbon Monoxide (CO)Good
112 Āµg/mĀ³
High levels reduce oxygen delivery in the body, compounding breathing difficulty on high-pollen days.
See the full San Marcos air quality report ā†’

Weather in San Marcos Today

šŸŒ¤ļø
Weather
80Ā°F
Overcast
Humidity
56%
Wind
16 mph SSE
Feels Like
81Ā°F
Pressure
1013 mb

Frequently Asked Questions

When pollen keeps winning, see an allergist

Pollen shifts week to week in San Marcos. If cetirizine (Zyrtec) or a steroid nasal spray stopped holding your symptoms down, or they drag on for months at a time, a board-certified allergist can test exactly what you react to and treat the cause instead of the symptom.

See 5 board-certified allergists in Texas ā†’

Get free daily pollen alerts

Morning alerts for San Marcos when pollen is high. One email a day, only when it matters.

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Allergy Guides and Resources

Seasonal pollen guides, daily city rankings, and practical tips for managing your allergies.

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