St. Paul Air Quality in October
Across 2019–2025, St. Paul's October air quality had a median AQI of 44 (Good) over 217 monitored days in the Minneapolis-St. Paul-Bloomington, MN-WI area. 0.0% of October days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 65.9% of days. The cleanest October on record here was 2019 (median AQI 37, 0 days above 100) and the worst was 2022 (median 55, 0 days above 100, peak AQI 90).
- Good: 61.8%
- Moderate: 38.2%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
Reduce Indoor Ozone in St. Paul
Today's main pollutant in St. Paul is ground-level ozone (AQI 25). 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 St. Paul in October?
Good on a typical day: median AQI 44 across 2019–2025, with 0.0% of October days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓61.8% of October days were Good (AQI 0–50), 38.2% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the October peak was 90.
- ✓Best October: 2019; worst October: 2022.
Frequently asked questions
What is the air quality like in St. Paul in October?▾
Across 2019–2025, the median daily AQI in St. Paul in October was 44 (Good). 61.8% of days were Good, 38.2% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is October a good time for outdoor exercise in St. Paul?▾
A typical October day in St. Paul 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 October days reached AQI 101+ in 2019–2025.
Which pollutant causes St. Paul's October air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 65.9% of October days in St. Paul. The highest October AQI recorded in 2019–2025 was 90 (Moderate), in 2022.
St. Paul October air quality, year by year
St. Paul October air quality by year (Minneapolis-St. Paul-Bloomington, MN-WI, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019cleanest | 31 | 37 | 0 | 74 | PM2.5 |
| 2020 | 31 | 43 | 0 | 66 | PM2.5 |
| 2021 | 31 | 42 | 0 | 88 | PM2.5 |
| 2022worst | 31 | 55 | 0 | 90 | PM2.5 |
| 2023 | 31 | 42 | 0 | 69 | PM2.5 |
| 2024 | 31 | 52 | 0 | 84 | PM2.5 |
| 2025 | 31 | 39 | 0 | 74 | PM2.5 |
What October air means in St. Paul
A typical October day in St. Paul 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 October days reached AQI 101+ in 2019–2025.
October's median AQI of 44 is below St. Paul's whole-year median of 50, making it one of the area's cleaner periods. Nationally, the median October AQI across every EPA metro area (102,872 metro-days, 2019–2025) is 38, so St. Paul runs above the national October norm; 0.0% of its October days topped AQI 100 versus 1.3% nationally (below average).
October is part of St. Paul's fall season (September, October, November); the fall page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in St. Paul
The latest EPA AirNow observation puts St. Paul's AQI at 25 (O3). The figures above are multi-year month statistics, not today's reading.
View current St. Paul air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Minneapolis-St. Paul-Bloomington, MN-WI), 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.