Hartford Air Quality in July
Across 2019–2025, Hartford's July air quality had a median AQI of 54 (Moderate) over 217 monitored days in the Hartford-West Hartford-East Hartford, CT area. 9.3% of July days (20 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 56.2% of days. The cleanest July on record here was 2020 (median AQI 52, 1 day above 100) and the worst was 2019 (median 57, 5 days above 100, peak AQI 154).
- Good: 38.7%
- Moderate: 52.1%
- Unhealthy for Sensitive Groups: 8.8%
- Unhealthy or worse: 0.5%
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How is the air in Hartford in July?
Moderate on a typical day: median AQI 54 across 2019–2025, with 9.3% of July days above AQI 100. Ground-level ozone is the main driver.
- ✓38.7% of July days were Good (AQI 0–50), 52.1% Moderate (51–100).
- ✓20 days of 217 reached AQI 101+; the July peak was 154.
- ✓Best July: 2020; worst July: 2019.
Frequently asked questions
What is the air quality like in Hartford in July?▾
Across 2019–2025, the median daily AQI in Hartford in July was 54 (Moderate). 38.7% of days were Good, 52.1% Moderate, and 9.3% 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 Hartford?▾
A typical July day in Hartford is Moderate (median AQI 54): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 11 of July days (9.3%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Hartford's July air quality problems?▾
Ground-level ozone set the daily AQI on 56.2% of July days in Hartford. The highest July AQI recorded in 2019–2025 was 154 (Unhealthy), in 2019.
Hartford July air quality, year by year
Hartford July air quality by year (Hartford-West Hartford-East Hartford, CT, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019worst | 31 | 57 | 5 | 154 | O3 |
| 2020cleanest | 31 | 52 | 1 | 129 | PM2.5 |
| 2021 | 31 | 52 | 4 | 136 | PM2.5 |
| 2022 | 31 | 57 | 3 | 136 | O3 |
| 2023 | 31 | 58 | 2 | 140 | O3 |
| 2024 | 31 | 52 | 2 | 115 | O3 |
| 2025 | 31 | 61 | 3 | 119 | O3 |
What July air means in Hartford
A typical July day in Hartford is Moderate (median AQI 54): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 11 of July days (9.3%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
July's median AQI of 54 is above Hartford's whole-year median of 43, making it one of the area's dirtier periods. Nationally, the median July AQI across every EPA metro area (103,858 metro-days, 2019–2025) is 47, so Hartford runs above the national July norm; 9.3% of its July days topped AQI 100 versus 3.6% nationally (above average).
July is part of Hartford's summer season (June, July, August); the summer page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Hartford
The latest EPA AirNow observation puts Hartford's AQI at 36 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Hartford air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Hartford-West Hartford-East Hartford, CT), 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.