Salt Lake City Air Quality in Winter
Across 2019–2025, Salt Lake City's winter (December–February) air quality had a median AQI of 51 (Moderate) over 632 monitored days in the Salt Lake City, UT area. 4.3% of winter days (27 of 632) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 61.1% of days. The cleanest winter on record here was 2025 (median AQI 50, 0 days above 100) and the worst was 2022 (median 57, 7 days above 100, peak AQI 128).
- Good: 48.6%
- Moderate: 47.2%
- Unhealthy for Sensitive Groups: 4.3%
- Unhealthy or worse: 0.0%
Extra Protection for Salt Lake City Homes
Air quality in Salt Lake City is moderate (AQI 52), with fine particles (PM2.5) the main concern. A True-HEPA purifier gives sensitive groups — kids, seniors and anyone with asthma or allergies — cleaner air indoors on days like today.
Recommended: Coway AP-1512HH Mighty — True HEPA + carbon · CADR ~246 CFM · rooms up to 361 sq ft
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How is the air in Salt Lake City in winter?
Moderate on a typical day: median AQI 51 across 2019–2025, with 4.3% of winter days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓48.6% of winter days were Good (AQI 0–50), 47.2% Moderate (51–100).
- ✓27 days of 632 reached AQI 101+; the winter peak was 149.
- ✓Cleanest month: February; worst month: December.
Frequently asked questions
What is the air quality like in Salt Lake City in winter?▾
Across 2019–2025, the median daily AQI in Salt Lake City in winter was 51 (Moderate). 48.6% of days were Good, 47.2% Moderate, and 4.3% reached Unhealthy for Sensitive Groups or worse, based on 632 monitored days in EPA's Air Quality System.
Is winter a good time for outdoor exercise in Salt Lake City?▾
A typical winter day in Salt Lake City is Moderate (median AQI 51): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 23 of winter days (4.3%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Salt Lake City's winter air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 61.1% of winter days in Salt Lake City. The highest winter AQI recorded in 2019–2025 was 149 (Unhealthy for Sensitive Groups), in 2022.
Salt Lake City winter air quality, year by year
Salt Lake City winter air quality by year (Salt Lake City, UT, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 90 | 54 | 6 | 136 | PM2.5 |
| 2020 | 91 | 51 | 1 | 106 | PM2.5 |
| 2021 | 90 | 46 | 4 | 149 | PM2.5 |
| 2022worst | 90 | 57 | 7 | 128 | PM2.5 |
| 2023 | 90 | 54 | 3 | 143 | PM2.5 |
| 2024 | 91 | 45 | 6 | 126 | PM2.5 |
| 2025cleanest | 90 | 50 | 0 | 93 | PM2.5 |
What winter air means in Salt Lake City
A typical winter day in Salt Lake City is Moderate (median AQI 51): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 23 of winter days (4.3%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Winter's median AQI of 51 is below Salt Lake City's whole-year median of 57, making it one of the area's cleaner periods. Nationally, the median Winter AQI across every EPA metro area (278,620 metro-days, 2019–2025) is 40, so Salt Lake City runs above the national Winter norm; 4.3% of its Winter days topped AQI 100 versus 0.6% nationally (above average).
Within the season, February is the cleanest month (median AQI 46, 2.0% of days above 100) and December the worst (median 54, 6.9% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Salt Lake City
The latest EPA AirNow observation puts Salt Lake City's AQI at 52 (PM2.5). The figures above are multi-year season statistics, not today's reading.
View current Salt Lake City air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Salt Lake City, UT), 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.