Dallas Air Quality in May

Across 2019–2025, Dallas's May air quality had a median AQI of 64 (Moderate) over 217 monitored days in the Dallas-Fort Worth-Arlington, TX area. 16.1% of May days (35 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 55.8% of days. The cleanest May on record here was 2021 (median AQI 51, 2 days above 100) and the worst was 2023 (median 76, 9 days above 100, peak AQI 136).

64
Median AQI
Moderate
16.1%
Days above AQI 100
35 of 217 days
108
90th percentile AQI
worst 1 day in 10
151
Peak AQI
Unhealthy
O3
Main pollutant
55.8% of days
22.6%
Good days
49 of 217
  • Good: 22.6%
  • Moderate: 61.3%
  • Unhealthy for Sensitive Groups: 15.2%
  • Unhealthy or worse: 0.9%

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QUICK ANSWER

How is the air in Dallas in May?

Moderate on a typical day: median AQI 64 across 2019–2025, with 16.1% of May days above AQI 100. Ground-level ozone is the main driver.

  • 22.6% of May days were Good (AQI 0–50), 61.3% Moderate (51–100).
  • 35 days of 217 reached AQI 101+; the May peak was 151.
  • Best May: 2021; worst May: 2023.

Frequently asked questions

What is the air quality like in Dallas in May?

Across 2019–2025, the median daily AQI in Dallas in May was 64 (Moderate). 22.6% of days were Good, 61.3% Moderate, and 16.1% 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 Dallas?

A typical May day in Dallas is Moderate (median AQI 64): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 6 of May days (16.1%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.

Which pollutant causes Dallas's May air quality problems?

Ground-level ozone set the daily AQI on 55.8% of May days in Dallas. The highest May AQI recorded in 2019–2025 was 151 (Unhealthy), in 2023.

Dallas May air quality, year by year

Dallas May air quality by year (Dallas-Fort Worth-Arlington, TX, EPA AQS daily AQI)

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
201931555133O3
202031614151O3
2021cleanest31512108PM2.5
202231645151O3
2023worst31769136O3
202431806126PM2.5
202531694136O3

What May air means in Dallas

A typical May day in Dallas is Moderate (median AQI 64): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 6 of May days (16.1%) 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 64 is above Dallas's whole-year median of 58, 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 Dallas runs above the national May norm; 16.1% of its May days topped AQI 100 versus 1.3% nationally (above average).

May is part of Dallas's spring season (March, April, May); the spring page pools all three months.

Activity-specific thresholds: running, cycling, kids' sports.

Right now in Dallas

The latest EPA AirNow observation puts Dallas's AQI at 55 (PM2.5). The figures above are multi-year month statistics, not today's reading.

View current Dallas air quality →

Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Dallas-Fort Worth-Arlington, 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.