San Antonio Air Quality in May
Across 2019–2025, San Antonio's May air quality had a median AQI of 62 (Moderate) over 217 monitored days in the San Antonio-New Braunfels, TX area. 7.0% of May days (15 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 62.2% of days. The cleanest May on record here was 2019 (median AQI 59, 0 days above 100) and the worst was 2024 (median 86, 11 days above 100, peak AQI 152).
- Good: 17.5%
- Moderate: 75.6%
- Unhealthy for Sensitive Groups: 6.5%
- Unhealthy or worse: 0.5%
Extra Protection for San Antonio Homes
Air quality in San Antonio is moderate (AQI 52), with fine particles (PM2.5) the main concern. A True-HEPA purifier gives sensitive groups — kids, seniors and anyone with asthma or allergies — cleaner air indoors on days like today.
Recommended: Coway AP-1512HH Mighty — True HEPA + carbon · CADR ~246 CFM · rooms up to 361 sq ft
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How is the air in San Antonio in May?
Moderate on a typical day: median AQI 62 across 2019–2025, with 7.0% of May days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓17.5% of May days were Good (AQI 0–50), 75.6% Moderate (51–100).
- ✓15 days of 217 reached AQI 101+; the May peak was 152.
- ✓Best May: 2019; worst May: 2024.
Frequently asked questions
What is the air quality like in San Antonio in May?▾
Across 2019–2025, the median daily AQI in San Antonio in May was 62 (Moderate). 17.5% of days were Good, 75.6% Moderate, and 7.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is May a good time for outdoor exercise in San Antonio?▾
A typical May day in San Antonio is Moderate (median AQI 62): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 14 of May days (7.0%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes San Antonio's May air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 62.2% of May days in San Antonio. The highest May AQI recorded in 2019–2025 was 152 (Unhealthy), in 2024.
San Antonio May air quality, year by year
San Antonio May air quality by year (San Antonio-New Braunfels, TX, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019cleanest | 31 | 59 | 0 | 97 | PM2.5 |
| 2020 | 31 | 59 | 0 | 100 | O3 |
| 2021 | 31 | 54 | 1 | 101 | PM2.5 |
| 2022 | 31 | 61 | 0 | 98 | PM2.5 |
| 2023 | 31 | 61 | 0 | 100 | O3 |
| 2024worst | 31 | 86 | 11 | 152 | PM2.5 |
| 2025 | 31 | 67 | 3 | 108 | O3 |
What May air means in San Antonio
A typical May day in San Antonio is Moderate (median AQI 62): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 14 of May days (7.0%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
May's median AQI of 62 is above San Antonio's whole-year median of 55, making it one of the area's dirtier periods. Nationally, the median May AQI across every EPA metro area (104,064 metro-days, 2019–2025) is 44, so San Antonio runs above the national May norm; 7.0% of its May days topped AQI 100 versus 1.3% nationally (above average).
May is part of San Antonio's spring season (March, April, May); the spring page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in San Antonio
The latest EPA AirNow observation puts San Antonio's AQI at 52 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current San Antonio air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (San Antonio-New Braunfels, TX), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.