Brownsville Median AQI 2021: Historical Air Quality Data
Explore 2021 air quality data for Brownsville, including the median AQI, seasonal patterns, pollution trends, and how air quality changed over the year.
Current Air Quality
Air quality is satisfactory, and air pollution poses little or no risk.
Brownsville Air Quality in 2021
Historical air quality data for Brownsville in 2021 shows how pollution levels have changed over time. Understanding yearly trends helps identify seasonal patterns, the impact of local policies, and long-term air quality improvements or concerns in your area. Check current conditions below for today's AQI reading.
View Current Brownsville Air Quality →Brownsville 2021 Air Quality Snapshot
Across 2021, Brownsville's median AQI was around 48 (Good), based on current readings and seasonal patterns for the Brownsville-Harlingen reporting area. That means a typical day fell near AQI 48, with the dominant pollutant being ground-level ozone (O3), which is common for the South Central region.
How Brownsville Air Quality Changed by Season in 2021
Spring (Mar–May): Usually Brownsville's cleanest stretch, with AQI near 30. Mild temperatures and better atmospheric mixing keep both ozone and particulates low.
Summer (Jun–Aug): AQI climbs toward 72 as heat and sunlight drive ozone formation to its yearly peak. Afternoons are the worst time to be outside.
Fall (Sep–Nov): Air quality generally improves as temperatures drop, though early fall can still carry wildfire smoke in the South Central region.
Winter (Dec–Feb): AQI near 50. Cold-air temperature inversions can trap PM2.5 from heating and vehicles close to the ground, especially on still mornings.
Is It Safe to Exercise Outside in Brownsville?
With Brownsville's AQI at 44 (Good), outdoor exercise is generally safe for most people. Conditions are good for running, cycling, and outdoor sports at any time of day.
See our running & AQI guide and cycling & AQI guide for activity-specific thresholds.
What's Causing Brownsville's Air Pollution?
In Brownsville, the leading pollutant is ground-level ozone (O3). As part of the South Central region, the main drivers of air pollution here are:
- •Oil and gas production and processing
- •Vehicle emissions from rapidly expanding metros
- •Extreme heat that amplifies ground-level ozone
- •Power-plant emissions from fossil-fuel generation
Dig deeper: Brownsville PM2.5 levels · Brownsville ozone levels
Air Purifier & Monitor Buying Guides
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PM2.5 Levels
Fine particulate matter data →
Ozone Levels
Ground-level ozone data →
Seasonal Guides
Air quality by season →
Health Effects
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Frequently Asked Questions About Brownsville Air Quality
What is the current air quality in Brownsville?
The current Air Quality Index (AQI) in Brownsville, TX is 44, which is considered good.
Is it safe to exercise outdoors in Brownsville?
Yes, with an AQI of 44, outdoor exercise is safe for everyone in Brownsville.
When is the best time of year to visit Brownsville for good air quality?
Spring and early fall typically offer the best air quality in Brownsville. Summer months may have elevated ozone levels, while winter can see higher PM2.5 from temperature inversions.
What causes air pollution in Brownsville?
Air pollution in Brownsville can come from vehicle emissions, industrial activity, construction, wildfires, and weather patterns. Local geography and seasonal factors also play a significant role.
Explore More Air Quality Data
Reduce Indoor Ozone in Brownsville
Today's main pollutant in Brownsville is ground-level ozone (AQI 44). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.
Compare activated-carbon purifiers (for gases & ozone):
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