Hartford Air Quality in April
Across 2019–2025, Hartford's April air quality had a median AQI of 44 (Good) over 210 monitored days in the Hartford-West Hartford-East Hartford, CT area. 1.5% of April days (3 of 210) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 88.1% of days. The cleanest April on record here was 2020 (median AQI 42, 0 days above 100) and the worst was 2023 (median 48, 2 days above 100, peak AQI 156).
- Good: 77.6%
- Moderate: 21.0%
- Unhealthy for Sensitive Groups: 1.0%
- Unhealthy or worse: 0.5%
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How is the air in Hartford in April?
Good on a typical day: median AQI 44 across 2019–2025, with 1.5% of April days above AQI 100. Ground-level ozone is the main driver.
- ✓77.6% of April days were Good (AQI 0–50), 21.0% Moderate (51–100).
- ✓3 days of 210 reached AQI 101+; the April peak was 156.
- ✓Best April: 2020; worst April: 2023.
Frequently asked questions
What is the air quality like in Hartford in April?▾
Across 2019–2025, the median daily AQI in Hartford in April was 44 (Good). 77.6% of days were Good, 21.0% Moderate, and 1.5% reached Unhealthy for Sensitive Groups or worse, based on 210 monitored days in EPA's Air Quality System.
Is April a good time for outdoor exercise in Hartford?▾
A typical April day in Hartford sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 67 of April days (1.5%) reached AQI 101+ in 2019–2025.
Which pollutant causes Hartford's April air quality problems?▾
Ground-level ozone set the daily AQI on 88.1% of April days in Hartford. The highest April AQI recorded in 2019–2025 was 156 (Unhealthy), in 2023.
Hartford April air quality, year by year
Hartford April 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 |
|---|---|---|---|---|---|
| 2019 | 30 | 45 | 0 | 67 | O3 |
| 2020cleanest | 30 | 42 | 0 | 54 | O3 |
| 2021 | 30 | 44 | 0 | 84 | O3 |
| 2022 | 30 | 43 | 0 | 64 | O3 |
| 2023worst | 30 | 48 | 2 | 156 | O3 |
| 2024 | 30 | 43 | 0 | 64 | O3 |
| 2025 | 30 | 45 | 1 | 101 | O3 |
What April air means in Hartford
A typical April day in Hartford sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 67 of April days (1.5%) reached AQI 101+ in 2019–2025.
April's median AQI of 44 is in line with Hartford's whole-year median of 43, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median April AQI across every EPA metro area (100,677 metro-days, 2019–2025) is 44, so Hartford runs in line with the national April norm; 1.5% of its April days topped AQI 100 versus 0.7% nationally (about the same).
April is part of Hartford's spring season (March, April, May); the spring 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.