Charleston, SC Air Quality in January
Across 2019–2025, Charleston's January air quality had a median AQI of 42 (Good) over 217 monitored days in the Charleston-North Charleston, SC area. 0.0% of January days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 79.7% of days. The cleanest January on record here was 2024 (median AQI 36, 0 days above 100) and the worst was 2023 (median 49, 0 days above 100, peak AQI 73).
- Good: 67.7%
- Moderate: 32.3%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
Reduce Indoor Ozone in Charleston
Today's main pollutant in Charleston is ground-level ozone (AQI 31). 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.
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How is the air in Charleston in January?
Good on a typical day: median AQI 42 across 2019–2025, with 0.0% of January days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓67.7% of January days were Good (AQI 0–50), 32.3% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the January peak was 73.
- ✓Best January: 2024; worst January: 2023.
Frequently asked questions
What is the air quality like in Charleston in January?▾
Across 2019–2025, the median daily AQI in Charleston in January was 42 (Good). 67.7% of days were Good, 32.3% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is January a good time for outdoor exercise in Charleston?▾
A typical January day in Charleston sits in the Good range (median AQI 42), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of January days reached AQI 101+ in 2019–2025.
Which pollutant causes Charleston's January air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 79.7% of January days in Charleston. The highest January AQI recorded in 2019–2025 was 73 (Moderate), in 2023.
Charleston January air quality, year by year
Charleston January air quality by year (Charleston-North Charleston, SC, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 42 | 0 | 66 | PM2.5 |
| 2020 | 31 | 38 | 0 | 58 | PM2.5 |
| 2021 | 31 | 46 | 0 | 69 | PM2.5 |
| 2022 | 31 | 47 | 0 | 73 | PM2.5 |
| 2023worst | 31 | 49 | 0 | 73 | PM2.5 |
| 2024cleanest | 31 | 36 | 0 | 59 | PM2.5 |
| 2025 | 31 | 46 | 0 | 58 | PM2.5 |
What January air means in Charleston
A typical January day in Charleston sits in the Good range (median AQI 42), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of January days reached AQI 101+ in 2019–2025.
January's median AQI of 42 is below Charleston's whole-year median of 47, making it one of the area's cleaner periods. Nationally, the median January AQI across every EPA metro area (95,602 metro-days, 2019–2025) is 39, so Charleston runs in line with the national January norm; 0.0% of its January days topped AQI 100 versus 0.7% nationally (about the same).
January is part of Charleston's winter season (December, January, February); the winter page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Charleston
The latest EPA AirNow observation puts Charleston's AQI at 31 (O3). The figures above are multi-year month statistics, not today's reading.
View current Charleston air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Charleston-North Charleston, SC), 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.