Durham Air Quality in July
Across 2019–2025, Durham's July air quality had a median AQI of 44 (Good) over 217 monitored days in the Durham-Chapel Hill, NC area. 0.5% of July days (1 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 50.2% of days. The cleanest July on record here was 2025 (median AQI 41, 0 days above 100) and the worst was 2023 (median 46, 1 day above 100, peak AQI 104).
- Good: 65.9%
- Moderate: 33.6%
- Unhealthy for Sensitive Groups: 0.5%
- Unhealthy or worse: 0.0%
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How is the air in Durham in July?
Good on a typical day: median AQI 44 across 2019–2025, with 0.5% of July days above AQI 100. Ground-level ozone is the main driver.
- ✓65.9% of July days were Good (AQI 0–50), 33.6% Moderate (51–100).
- ✓1 day of 217 reached AQI 101+; the July peak was 104.
- ✓Best July: 2025; worst July: 2023.
Frequently asked questions
What is the air quality like in Durham in July?▾
Across 2019–2025, the median daily AQI in Durham in July was 44 (Good). 65.9% of days were Good, 33.6% Moderate, and 0.5% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is July a good time for outdoor exercise in Durham?▾
A typical July day in Durham sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of July days reached AQI 101+ in 2019–2025.
Which pollutant causes Durham's July air quality problems?▾
Ground-level ozone set the daily AQI on 50.2% of July days in Durham. The highest July AQI recorded in 2019–2025 was 104 (Unhealthy for Sensitive Groups), in 2023.
Durham July air quality, year by year
Durham July air quality by year (Durham-Chapel Hill, NC, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 48 | 0 | 67 | O3 |
| 2020 | 31 | 44 | 0 | 77 | PM2.5 |
| 2021 | 31 | 54 | 0 | 89 | PM2.5 |
| 2022 | 31 | 42 | 0 | 53 | O3 |
| 2023worst | 31 | 46 | 1 | 104 | O3 |
| 2024 | 31 | 49 | 0 | 77 | PM2.5 |
| 2025cleanest | 31 | 41 | 0 | 63 | PM2.5 |
What July air means in Durham
A typical July day in Durham sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of July days reached AQI 101+ in 2019–2025.
July's median AQI of 44 is in line with Durham's whole-year median of 44, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median July AQI across every EPA metro area (103,858 metro-days, 2019–2025) is 47, so Durham runs in line with the national July norm; 0.5% of its July days topped AQI 100 versus 3.6% nationally (below average).
July is part of Durham's summer season (June, July, August); the summer page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Durham
The latest EPA AirNow observation puts Durham's AQI at 41 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Durham air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Durham-Chapel Hill, NC), 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.