Brownsville Air Quality in Summer
Across 2019–2025, Brownsville's summer (June–August) air quality had a median AQI of 55 (Moderate) over 644 monitored days in the Brownsville-Harlingen, TX area. 2.8% of summer days (18 of 644) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 93.5% of days. The cleanest summer on record here was 2021 (median AQI 54, 0 days above 100) and the worst was 2024 (median 56, 10 days above 100, peak AQI 157).
- Good: 35.1%
- Moderate: 62.1%
- Unhealthy for Sensitive Groups: 2.2%
- Unhealthy or worse: 0.6%
Improve Indoor Air Quality
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How is the air in Brownsville in summer?
Moderate on a typical day: median AQI 55 across 2019–2025, with 2.8% of summer days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓35.1% of summer days were Good (AQI 0–50), 62.1% Moderate (51–100).
- ✓18 days of 644 reached AQI 101+; the summer peak was 184.
- ✓Cleanest month: August; worst month: June.
Frequently asked questions
What is the air quality like in Brownsville in summer?▾
Across 2019–2025, the median daily AQI in Brownsville in summer was 55 (Moderate). 35.1% of days were Good, 62.1% Moderate, and 2.8% reached Unhealthy for Sensitive Groups or worse, based on 644 monitored days in EPA's Air Quality System.
Is summer a good time for outdoor exercise in Brownsville?▾
A typical summer day in Brownsville is Moderate (median AQI 55): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 36 of summer days (2.8%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Brownsville's summer air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 93.5% of summer days in Brownsville. The highest summer AQI recorded in 2019–2025 was 184 (Unhealthy), in 2024.
Brownsville summer air quality, year by year
Brownsville summer air quality by year (Brownsville-Harlingen, TX, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 92 | 55 | 0 | 87 | PM2.5 |
| 2020 | 92 | 55 | 3 | 184 | PM2.5 |
| 2021cleanest | 92 | 54 | 0 | 92 | PM2.5 |
| 2022 | 92 | 53 | 3 | 120 | PM2.5 |
| 2023 | 92 | 58 | 2 | 104 | PM2.5 |
| 2024worst | 92 | 56 | 10 | 157 | PM2.5 |
| 2025 | 92 | 54 | 0 | 87 | PM2.5 |
What summer air means in Brownsville
A typical summer day in Brownsville is Moderate (median AQI 55): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 36 of summer days (2.8%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Summer's median AQI of 55 is in line with Brownsville's whole-year median of 52, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median Summer AQI across every EPA metro area (308,645 metro-days, 2019–2025) is 46, so Brownsville runs above the national Summer norm; 2.8% of its Summer days topped AQI 100 versus 3.6% nationally (about the same).
Within the season, August is the cleanest month (median AQI 51, 0.5% of days above 100) and June the worst (median 58, 7.1% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Brownsville
The latest EPA AirNow observation puts Brownsville's AQI at 43 (PM2.5). The figures above are multi-year season statistics, not today's reading.
View current Brownsville air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Brownsville-Harlingen, 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.