Minnesota · County air quality · 2025

Blue Earth County, Minnesota

Median AQI 42 (Good). 65.3% of monitored days rated Good, direct from EPA Air Quality System stations.

42
Median AQI
65.3%
Good-air days
5
Unhealthy days
23%
Cleaner than US counties

Blue Earth County's 2025 annual median AQI is 42 (Good), with 65.3% Good days

According to the U.S. EPA Air Quality System, Blue Earth County, Minnesota posted a 2025 median AQI of 42 (Good) across 357 monitored days, with 65.3% rated Good and 5 unhealthy or worse. This is an annual comparison, not today's advisory.

Data source EPA Air Quality System (AQS)

Cleaner than US
Blue Earth County's 65.3% Good-day share places it cleaner than 23% of US counties in 2025.
Closest median-AQI peer
Ada County (74.0% Good, median AQI 42) is the closest nationwide median-AQI peer to Blue Earth County.
2024–2025 trend
Blue Earth County's floor-qualifying Good-day share is improving from 2024 to 2025 (61.6% → 65.3%).
Median AQI
Median AQI: 42

According to the 2025 EPA AQS county release on PlainAirData, Blue Earth County, Minnesota ranks #581 of 951 by median AQI (42) and #728 by good-day share (65.3%). 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

2024 → 2025
  • Blue Earth County's peak single-day AQI rose from 80 to 180 between the 2024 and 2025 EPA annual releases, a change of +100 points.
  • Blue Earth County's Unhealthy-category days rose from 0 to 5 between the 2024 and 2025 EPA annual releases, a change of +5 days.
  • Blue Earth County's Good-day share rose from 61.6% to 65.3% between the 2024 and 2025 EPA annual releases, a change of +3.6 percentage points.
  • Blue Earth County's median AQI fell from 45 to 42 between the 2024 and 2025 EPA annual releases, a change of -3 points.

Compared against 146 monitored days in 2024 and 357 in 2025. These are arithmetic differences between two stored EPA annual summaries, not a cause claim or a live advisory.

National release changes Two-year CSV

Data updated August 2026

Blue Earth County AQI category distribution Stacked-segment bar showing the share of monitored days that fell in each EPA AQI category, Good, Moderate, USG, Unhealthy, Very Unhealthy, Hazardous, with median AQI marker. AQI category distribution 357 monitored days G M Median AQI 42 0 50 100 150 200 300 500 Blue Earth County
  • Good · 233 d · 65.3%
  • Moderate · 110 d · 30.8%
  • USG · 9 d · 2.5%
  • Unhealthy · 5 d · 1.4%

How did Blue Earth County's air break down in 2025?

Across 357 monitored days, 233 fell in the Good band (AQI 0–50) and 5 reached Unhealthy or worse. The worst single day peaked at AQI 180 (Unhealthy).

EPA AQS →
Blue Earth County, Good days share 65.3%
National avg

Share of monitored days at AQI 0-50 (Good band).

Blue Earth County, Unhealthy-or-worse share 14.0%
National avg

Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).

Where Blue Earth County sits nationally

COUNT-derived placement among 951 US counties with at least 100 monitored days in 2025. Blue Earth County's Good-day share is 65.3% - cleaner than 23% of that comparison set.

Blue Earth County Good-day share vs. every US county

Share of monitored days in the Good band (AQI 0–50) - EPA AQS annual release

65.3% 23rd percentile higher than 23% of 951 US counties

0.0%–5.0%: 0 US counties (0%). Below this entry. 5.0%–10.0%: 1 US counties (0%). Below this entry. 10.0%–15.0%: 4 US counties (0%). Below this entry. 15.0%–20.0%: 4 US counties (0%). Below this entry. 20.0%–25.0%: 1 US counties (0%). Below this entry. 25.0%–30.0%: 5 US counties (1%). Below this entry. 30.0%–35.0%: 9 US counties (1%). Below this entry. 35.0%–40.0%: 4 US counties (0%). Below this entry. 40.0%–45.0%: 16 US counties (2%). Below this entry. 45.0%–50.0%: 16 US counties (2%). Below this entry. 50.0%–55.0%: 32 US counties (3%). Below this entry. 55.0%–60.0%: 50 US counties (5%). Below this entry. 60.0%–65.0%: 77 US counties (8%). Below this entry. 65.0%–70.0%: 93 US counties (10%). This entry sits in this band. 70.0%–75.0%: 109 US counties (11%). Above this entry. 75.0%–80.0%: 114 US counties (12%). Above this entry. 80.0%–85.0%: 123 US counties (13%). Above this entry. 85.0%–90.0%: 99 US counties (10%). Above this entry. 90.0%–95.0%: 117 US counties (12%). Above this entry. 95.0%–100.0%: 70 US counties (7%). Above this entry. 100.0%–105.0%: 7 US counties (1%). Above this entry. This county 0.0% 100% every floor-qualified US county, bucketed by value

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 Blue Earth County.

Blue Earth County, Minnesota criteria pollutant distribution Stratified-band visualization showing the share of monitored days each criteria pollutant (PM2.5, PM10, O3, NO2, CO) was the primary AQI driver. PM2.5 · 71.7% Ozone · 28.3% 0% 25% 50% 75% 100% Blue Earth County, Minnesota · 357 monitored days Criteria pollutant column
  • PM2.5 · 256 days · 71.7%
  • Ozone · 101 days · 28.3%

2024 daily-monitor rhythm in Blue Earth County

Month-by-month median AQI from EPA day-level county monitors (146 reported days in 2024). Jul posted the highest typical readings (median AQI 51, peak 72); Nov was cleanest at median 30.

0 10 20 30 40 50 60 Jul Aug Sep Oct Nov 51 45 43 51 30
Blue Earth County median daily AQI by calendar month (2024, EPA daily county file)

Health Impact Assessment

Moderate

Blue Earth County's air quality is rated Moderate based on 65.3% good air days. There were 5 unhealthy days in 2025 when outdoor activity should be limited.

Air quality is acceptable most days, but 9 days reached "Unhealthy for Sensitive Groups" (AQI 101-150) and peak AQI reached 180. Sensitive groups should monitor real-time conditions at AirNow.gov.

The dominant pollutant is PM2.5, driving AQI on 256 of 357 monitored days.

5-Year Air Quality Trend

Air quality is improving in Blue Earth County. Highest Good-day share: 2025 (65.3%, 233 of 357 monitored days).

Year Good Moderate USG Unhealthy Median AQI
2024 90 56 0 0 45
2025 233 110 9 5 42

How does Blue Earth County compare?

How Blue Earth County compares

Good-day share worse than typical
Blue Earth County 65.3%
Ada County, Idaho 74.0%
Typical US county 76.0%
Median AQI worse than typical
Blue Earth County 42
Ada County, Idaho 42
Typical US county 39
Unhealthy days / yr worse than typical
Blue Earth County 5
Ada County, Idaho 0
Typical US county 1

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 Blue Earth County, Minnesota · 2020–2025

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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.