St. Paul Air Quality in Spring
Across 2019–2025, St. Paul's spring (March–May) air quality had a median AQI of 47 (Good) over 644 monitored days in the Minneapolis-St. Paul-Bloomington, MN-WI area. 1.5% of spring days (10 of 644) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 56.4% of days. The cleanest spring on record here was 2022 (median AQI 43, 0 days above 100) and the worst was 2023 (median 52, 8 days above 100, peak AQI 154).
- Good: 59.8%
- Moderate: 38.7%
- Unhealthy for Sensitive Groups: 1.2%
- Unhealthy or worse: 0.3%
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 spring?
Good on a typical day: median AQI 47 across 2019–2025, with 1.5% of spring days above AQI 100. Ground-level ozone is the main driver.
- ✓59.8% of spring days were Good (AQI 0–50), 38.7% Moderate (51–100).
- ✓10 days of 644 reached AQI 101+; the spring peak was 154.
- ✓Cleanest month: March; worst month: May.
Frequently asked questions
What is the air quality like in St. Paul in spring?▾
Across 2019–2025, the median daily AQI in St. Paul in spring was 47 (Good). 59.8% of days were Good, 38.7% Moderate, and 1.5% reached Unhealthy for Sensitive Groups or worse, based on 644 monitored days in EPA's Air Quality System.
Is spring a good time for outdoor exercise in St. Paul?▾
A typical spring day in St. Paul sits in the Good range (median AQI 47), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 67 of spring days (1.5%) reached AQI 101+ in 2019–2025.
Which pollutant causes St. Paul's spring air quality problems?▾
Ground-level ozone set the daily AQI on 56.4% of spring days in St. Paul. The highest spring AQI recorded in 2019–2025 was 154 (Unhealthy), in 2023.
St. Paul spring air quality, year by year
St. Paul spring 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 |
|---|---|---|---|---|---|
| 2019 | 92 | 52 | 0 | 87 | O3 |
| 2020 | 92 | 47 | 0 | 68 | PM2.5 |
| 2021 | 92 | 47 | 0 | 89 | O3 |
| 2022cleanest | 92 | 43 | 0 | 77 | O3 |
| 2023worst | 92 | 52 | 8 | 154 | O3 |
| 2024 | 92 | 44 | 2 | 152 | O3 |
| 2025 | 92 | 45 | 0 | 97 | O3 |
What spring air means in St. Paul
A typical spring day in St. Paul sits in the Good range (median AQI 47), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 67 of spring days (1.5%) reached AQI 101+ in 2019–2025.
Spring's median AQI of 47 is in line with St. Paul's whole-year median of 50, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median Spring AQI across every EPA metro area (307,196 metro-days, 2019–2025) is 43, so St. Paul runs above the national Spring norm; 1.5% of its Spring days topped AQI 100 versus 0.8% nationally (about the same).
Within the season, March is the cleanest month (median AQI 47, 0.0% of days above 100) and May the worst (median 49, 4.1% above 100).
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 season 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.