Cleveland Air Quality in December
Across 2019–2025, Cleveland's December air quality had a median AQI of 56 (Moderate) over 217 monitored days in the Cleveland-Elyria, OH area. 0.5% of December days (1 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 93.1% of days. The cleanest December on record here was 2024 (median AQI 52, 0 days above 100) and the worst was 2020 (median 56, 1 day above 100, peak AQI 105).
- Good: 31.8%
- Moderate: 67.7%
- Unhealthy for Sensitive Groups: 0.5%
- Unhealthy or worse: 0.0%
Reduce Indoor Ozone in Cleveland
Today's main pollutant in Cleveland is ground-level ozone (AQI 44). 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 Cleveland in December?
Moderate on a typical day: median AQI 56 across 2019–2025, with 0.5% of December days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓31.8% of December days were Good (AQI 0–50), 67.7% Moderate (51–100).
- ✓1 day of 217 reached AQI 101+; the December peak was 105.
- ✓Best December: 2024; worst December: 2020.
Frequently asked questions
What is the air quality like in Cleveland in December?▾
Across 2019–2025, the median daily AQI in Cleveland in December was 56 (Moderate). 31.8% of days were Good, 67.7% Moderate, and 0.5% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is December a good time for outdoor exercise in Cleveland?▾
A typical December day in Cleveland is Moderate (median AQI 56): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of December days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Cleveland's December air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 93.1% of December days in Cleveland. The highest December AQI recorded in 2019–2025 was 105 (Unhealthy for Sensitive Groups), in 2020.
Cleveland December air quality, year by year
Cleveland December air quality by year (Cleveland-Elyria, OH, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 62 | 0 | 89 | PM2.5 |
| 2020worst | 31 | 56 | 1 | 105 | PM2.5 |
| 2021 | 31 | 55 | 0 | 77 | PM2.5 |
| 2022 | 31 | 55 | 0 | 88 | PM2.5 |
| 2023 | 31 | 57 | 0 | 94 | PM2.5 |
| 2024cleanest | 31 | 52 | 0 | 73 | PM2.5 |
| 2025 | 31 | 55 | 0 | 75 | PM2.5 |
What December air means in Cleveland
A typical December day in Cleveland is Moderate (median AQI 56): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of December days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
December's median AQI of 56 is in line with Cleveland's whole-year median of 55, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median December AQI across every EPA metro area (95,590 metro-days, 2019–2025) is 39, so Cleveland runs above the national December norm; 0.5% of its December days topped AQI 100 versus 0.7% nationally (about the same).
December is part of Cleveland's winter season (December, January, February); the winter page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Cleveland
The latest EPA AirNow observation puts Cleveland's AQI at 44 (O3). The figures above are multi-year month statistics, not today's reading.
View current Cleveland air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Cleveland-Elyria, OH), 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.