Brownsville Air Quality in Winter
Across 2019–2025, Brownsville's winter (December–February) air quality had a median AQI of 50 (Good) over 632 monitored days in the Brownsville-Harlingen, TX area. 1.1% of winter days (7 of 632) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 75.0% of days. The cleanest winter on record here was 2022 (median AQI 42, 0 days above 100) and the worst was 2024 (median 57, 6 days above 100, peak AQI 120).
- Good: 50.6%
- Moderate: 48.3%
- Unhealthy for Sensitive Groups: 1.1%
- Unhealthy or worse: 0.0%
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How is the air in Brownsville in winter?
Good on a typical day: median AQI 50 across 2019–2025, with 1.1% of winter days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓50.6% of winter days were Good (AQI 0–50), 48.3% Moderate (51–100).
- ✓7 days of 632 reached AQI 101+; the winter peak was 120.
- ✓Cleanest month: December; worst month: February.
Frequently asked questions
What is the air quality like in Brownsville in winter?▾
Across 2019–2025, the median daily AQI in Brownsville in winter was 50 (Good). 50.6% of days were Good, 48.3% Moderate, and 1.1% reached Unhealthy for Sensitive Groups or worse, based on 632 monitored days in EPA's Air Quality System.
Is winter a good time for outdoor exercise in Brownsville?▾
A typical winter day in Brownsville sits in the Good range (median AQI 50), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 91 of winter days (1.1%) reached AQI 101+ in 2019–2025.
Which pollutant causes Brownsville's winter air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 75.0% of winter days in Brownsville. The highest winter AQI recorded in 2019–2025 was 120 (Unhealthy for Sensitive Groups), in 2024.
Brownsville winter air quality, year by year
Brownsville winter air quality by year (Brownsville-Harlingen, TX, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 90 | 44 | 0 | 91 | PM2.5 |
| 2020 | 91 | 46 | 0 | 76 | PM2.5 |
| 2021 | 90 | 52 | 0 | 99 | PM2.5 |
| 2022cleanest | 90 | 42 | 0 | 77 | PM2.5 |
| 2023 | 90 | 55 | 0 | 96 | PM2.5 |
| 2024worst | 91 | 57 | 6 | 120 | PM2.5 |
| 2025 | 90 | 54 | 1 | 109 | PM2.5 |
What winter air means in Brownsville
A typical winter day in Brownsville sits in the Good range (median AQI 50), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 91 of winter days (1.1%) reached AQI 101+ in 2019–2025.
Winter's median AQI of 50 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 Winter AQI across every EPA metro area (278,620 metro-days, 2019–2025) is 40, so Brownsville runs above the national Winter norm; 1.1% of its Winter days topped AQI 100 versus 0.6% nationally (about the same).
Within the season, December is the cleanest month (median AQI 51, 0.5% of days above 100) and February the worst (median 53, 2.0% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Brownsville
The latest EPA AirNow observation puts Brownsville's AQI at 47 (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.