Minnesota · County air quality · 2025
Stearns County, Minnesota
Median AQI 37 (Good). 75.6% of monitored days rated Good, direct from EPA Air Quality System stations.
- 37
- Median AQI
- 75.6%
- Good-air days
- 3
- Unhealthy days
- 46%
- Cleaner than US counties
Stearns County's 2025 annual median AQI is 37 (Good), with 75.6% Good days
According to the U.S. EPA Air Quality System, Stearns County, Minnesota posted a 2025 median AQI of 37 (Good) across 357 monitored days, with 75.6% rated Good and 3 unhealthy or worse. This is an annual comparison, not today's advisory.
Data source EPA Air Quality System (AQS)
- Cleaner than US
- Stearns County's 75.6% Good-day share places it cleaner than 46% of US counties in 2025.
- Closest median-AQI peer
- Alachua County (88.7% Good, median AQI 37) is the closest nationwide median-AQI peer to Stearns County.
- 2020–2025 trend
- Stearns County's floor-qualifying Good-day share is worsening from 2020 to 2025 (84.4% → 75.6%).
- Median AQI
- Median AQI: 37
According to the 2025 EPA AQS county release on PlainAirData, Stearns County, Minnesota ranks #286 of 951 by median AQI (37) and #514 by good-day share (75.6%). Ponce County, Puerto Rico is #1 of 951 by median AQI (3, 91.4% Good days) at good-day-share #159 ≠ largest of 7 at 100.0% Good days #1 by good-day share (100.0%, median AQI 9) at median-AQI #7.
Annual release change
What changed in the 2025 EPA annual release
- Stearns County's peak single-day AQI rose from 97 to 165 between the 2024 and 2025 EPA annual releases, a change of +68 points.
- Stearns County's Unhealthy-category days rose from 0 to 3 between the 2024 and 2025 EPA annual releases, a change of +3 days.
- Stearns County's Good-day share fell from 77.0% to 75.6% between the 2024 and 2025 EPA annual releases, a change of -1.4 percentage points.
Data updated August 2026
- Good · 270 d · 75.6%
- Moderate · 76 d · 21.3%
- USG · 8 d · 2.2%
- Unhealthy · 3 d · 0.8%
How did Stearns County's air break down in 2025?
Across 357 monitored days, 270 fell in the Good band (AQI 0–50) and 3 reached Unhealthy or worse. The worst single day peaked at AQI 165 (Unhealthy).
EPA AQS →Share of monitored days at AQI 0-50 (Good band).
Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).
Where Stearns County sits nationally
COUNT-derived placement among 951 US counties with at least 100 monitored days in 2025. Stearns County's Good-day share is 75.6% - cleaner than 46% of that comparison set.
Stearns County Good-day share vs. every US county
Share of monitored days in the Good band (AQI 0–50) - EPA AQS annual release
75.6% 46th percentile higher than 46% of 951 US counties
Each bar is a band; taller bars hold more US counties. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source U.S. Environmental Protection Agency, Air Quality System (AQS) · 2025
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Stearns County.
- PM2.5 · 204 days · 57.1%
- Ozone · 153 days · 42.9%
2024 daily-monitor rhythm in Stearns County
Month-by-month median AQI from EPA day-level county monitors (366 reported days in 2024). Jul posted the highest typical readings (median AQI 49, peak 77); Nov was cleanest at median 26. Summer months (Jun–Aug) averaged median AQI 45 vs 38 in Dec–Feb.
Five-year seasonal record
EPA day-level county files · 2020–20241,736 daily readings show a recurring local pattern: Jun has the highest matched-month median AQI (51), while Nov is lowest (31). Each cell is that month’s median daily AQI, not a current-air forecast.
Lower AQI is better. The colors summarize EPA AQI bands; gaps mean the county had no day-level record for that month.
Health Impact Assessment
Stearns County's air quality is rated Good based on 75.6% good air days. There were 3 unhealthy days in 2025 when outdoor activity should be limited.
Air quality is acceptable most days, but 8 days reached "Unhealthy for Sensitive Groups" (AQI 101-150) and peak AQI reached 165. Sensitive groups should monitor real-time conditions at AirNow.gov.
The dominant pollutant is PM2.5, driving AQI on 204 of 357 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Stearns County. Highest Good-day share: 2020 (84.4%, 309 of 366 monitored days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 309 | 57 | 0 | 0 | 36 | 80 |
| 2021 | 261 | 95 | 3 | 2 | 40 | 252 |
| 2022 | 204 | 73 | 0 | 0 | 39 | 78 |
| 2023 | 199 | 152 | 11 | 3 | 48 | 184 |
| 2024 | 282 | 84 | 0 | 0 | 39 | 97 |
| 2025 | 270 | 76 | 8 | 3 | 37 | 165 |
How does Stearns County compare?
How Stearns County compares
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025 (aqs.epa.gov). For current conditions (not shown here — this page is historical annual data), see EPA AirNow (airnow.gov). See our methodology for how AQI, median, and coverage figures are computed.
Informational only, not professional advice. Data from EPA AQS. See our disclaimer. Spotted a figure that looks wrong? Report a correction.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files for Stearns County, Minnesota · 2020–2025
Download this county's annual AQI row as CSV , with the same EPA fields and denominator shown on this page.
Every figure on PlainAirData is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.