Worcester Air Quality in Spring
Across 2019–2025, Worcester's spring (March–May) air quality had a median AQI of 44 (Good) over 644 monitored days in the Worcester, MA-CT area. 0.2% of spring days (1 of 644) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 63.7% of days. The cleanest spring on record here was 2024 (median AQI 39, 0 days above 100) and the worst was 2023 (median 44, 1 day above 100, peak AQI 112).
- Good: 77.0%
- Moderate: 22.8%
- Unhealthy for Sensitive Groups: 0.2%
- Unhealthy or worse: 0.0%
Reduce Indoor Ozone in Worcester
Today's main pollutant in Worcester is ground-level ozone (AQI 32). 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.
Recommended: Levoit Core 300 — True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft
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How is the air in Worcester in spring?
Good on a typical day: median AQI 44 across 2019–2025, with 0.2% of spring days above AQI 100. Ground-level ozone is the main driver.
- ✓77.0% of spring days were Good (AQI 0–50), 22.8% Moderate (51–100).
- ✓1 day of 644 reached AQI 101+; the spring peak was 112.
- ✓Cleanest month: May; worst month: April.
Frequently asked questions
What is the air quality like in Worcester in spring?▾
Across 2019–2025, the median daily AQI in Worcester in spring was 44 (Good). 77.0% of days were Good, 22.8% Moderate, and 0.2% reached Unhealthy for Sensitive Groups or worse, based on 644 monitored days in EPA's Air Quality System.
Is spring a good time for outdoor exercise in Worcester?▾
A typical spring day in Worcester 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 spring days reached AQI 101+ in 2019–2025.
Which pollutant causes Worcester's spring air quality problems?▾
Ground-level ozone set the daily AQI on 63.7% of spring days in Worcester. The highest spring AQI recorded in 2019–2025 was 112 (Unhealthy for Sensitive Groups), in 2023.
Worcester spring air quality, year by year
Worcester spring air quality by year (Worcester, MA-CT, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 92 | 45 | 0 | 71 | O3 |
| 2020 | 92 | 43 | 0 | 67 | O3 |
| 2021 | 92 | 47 | 0 | 84 | PM2.5 |
| 2022 | 92 | 48 | 0 | 71 | PM2.5 |
| 2023worst | 92 | 44 | 1 | 112 | O3 |
| 2024cleanest | 92 | 39 | 0 | 80 | O3 |
| 2025 | 92 | 43 | 0 | 87 | O3 |
What spring air means in Worcester
A typical spring day in Worcester 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 spring days reached AQI 101+ in 2019–2025.
Spring's median AQI of 44 is in line with Worcester's whole-year median of 43, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median Spring AQI across every EPA metro area (307,196 metro-days, 2019–2025) is 43, so Worcester runs in line with the national Spring norm; 0.2% of its Spring days topped AQI 100 versus 0.8% nationally (about the same).
Within the season, May is the cleanest month (median AQI 43, 0.0% of days above 100) and April the worst (median 44, 0.5% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Worcester
The latest EPA AirNow observation puts Worcester's AQI at 32 (O3). The figures above are multi-year season statistics, not today's reading.
View current Worcester air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Worcester, MA-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.