Salt Lake City Air Quality in September
Across 2019–2025, Salt Lake City's September air quality had a median AQI of 58 (Moderate) over 210 monitored days in the Salt Lake City, UT area. 8.6% of September days (18 of 210) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 74.8% of days. The cleanest September on record here was 2019 (median AQI 52, 0 days above 100) and the worst was 2021 (median 71, 6 days above 100, peak AQI 151).
- Good: 31.4%
- Moderate: 60.0%
- Unhealthy for Sensitive Groups: 8.1%
- Unhealthy or worse: 0.5%
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 September?
Moderate on a typical day: median AQI 58 across 2019–2025, with 8.6% of September days above AQI 100. Ground-level ozone is the main driver.
- ✓31.4% of September days were Good (AQI 0–50), 60.0% Moderate (51–100).
- ✓18 days of 210 reached AQI 101+; the September peak was 151.
- ✓Best September: 2019; worst September: 2021.
Frequently asked questions
What is the air quality like in Salt Lake City in September?▾
Across 2019–2025, the median daily AQI in Salt Lake City in September was 58 (Moderate). 31.4% of days were Good, 60.0% Moderate, and 8.6% reached Unhealthy for Sensitive Groups or worse, based on 210 monitored days in EPA's Air Quality System.
Is September a good time for outdoor exercise in Salt Lake City?▾
A typical September day in Salt Lake City is Moderate (median AQI 58): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 12 of September days (8.6%) 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 September air quality problems?▾
Ground-level ozone set the daily AQI on 74.8% of September days in Salt Lake City. The highest September AQI recorded in 2019–2025 was 151 (Unhealthy), in 2021.
Salt Lake City September air quality, year by year
Salt Lake City September air quality by year (Salt Lake City, UT, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019cleanest | 30 | 52 | 0 | 93 | O3 |
| 2020 | 30 | 66 | 2 | 114 | PM2.5 |
| 2021worst | 30 | 71 | 6 | 151 | O3 |
| 2022 | 30 | 61 | 6 | 136 | O3 |
| 2023 | 30 | 53 | 0 | 100 | O3 |
| 2024 | 30 | 61 | 3 | 144 | O3 |
| 2025 | 30 | 52 | 1 | 122 | O3 |
What September air means in Salt Lake City
A typical September day in Salt Lake City is Moderate (median AQI 58): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 12 of September days (8.6%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
September's median AQI of 58 is in line with Salt Lake City's whole-year median of 57, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median September AQI across every EPA metro area (100,699 metro-days, 2019–2025) is 43, so Salt Lake City runs above the national September norm; 8.6% of its September days topped AQI 100 versus 2.7% nationally (above average).
September is part of Salt Lake City's fall season (September, October, November); the fall page pools all three months.
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 month 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.