Median AQI
38
Good
Michigan · County air quality · 2025
Huron County, Michigan
Median AQI 38 (Good). 89.6% of monitored days rated Good, direct from EPA Air Quality System stations.
- 38
- Median AQI
- 89.6%
- Good-air days
- 0
- Unhealthy days
- 75%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Huron County's air is good on balance, cleaner than most US counties, a median AQI of 38 with 89.6% of 212 monitored days in the Good band, driven mainly by Ozone.
- 38
- median AQI · Good
- 89.6%
- days rated Good
- Ozone
- main pollutant
- 75%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 108.
Data updated July 2026
- Good · 190 d · 89.6%
- Moderate · 20 d · 9.4%
- USG · 2 d · 0.9%
How did Huron County's air break down in 2025?
Across 212 monitored days, 190 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 108 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 212 days monitored. Median AQI: 38 (Good).
Insights: Huron County, Michigan. EPA monitors recorded a median Air Quality Index of 38 across 212 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 190 (90%) fell in the Good band (AQI 0–50), 20 (9%) registered Moderate readings, and 2 (1%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 51, while the worst single-day peak hit 108 (USG). Residents averaged about 26.9 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (212 days). Across the 2020–2025 trend window, good days shifted by -56 and the median AQI moved +2 points, placing the multi-year trajectory at stable. The worst single reading over the 2020–2025 window was AQI 108, usg but never Unhealthy. Nearby counties show comparable readings: Allegan (71.2% good, AQI 43); Bay (71.8% good, AQI 38); Benzie (91.1% good, AQI 35); Berrien (80.9% good, AQI 41); Cass (85.3% good, AQI 40); Clinton (90.2% good, AQI 39).
Air Quality Summary
Good Days
89.6%
190 of 212 monitored days
14.6pp vs 75% target
Max AQI Recorded
108
USG
Health Grade
Good
90th-pct AQI 51
Huron County, Good days share 89.6%
National avg
Share of monitored days at AQI 0-50 (Good band).
Huron County, Unhealthy-or-worse share 0.0%
National avg
Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).
AQI Day Breakdown (2025)
Distribution of 212 monitored days across EPA AQI categories.
Good
190
90%
Moderate
20
9%
USG
2
1%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Huron County.
- Ozone · 212 days · 100.0%
Health Impact Assessment
Good
Huron County's air quality is rated Good based on 89.6% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 89.6% of monitored days in 2025, with a median AQI of 38. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is Ozone, driving AQI on 212 of 212 monitored days.
5-Year Air Quality Trend
Air quality is stable in Huron County. Best year: 2020 (246 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 246 | 13 | 7 | 0 | 36 | 150 |
| 2021 | 221 | 23 | 2 | 0 | 37 | 101 |
| 2022 | 227 | 15 | 1 | 0 | 35 | 122 |
| 2023 | 209 | 27 | 4 | 0 | 39 | 133 |
| 2024 | 216 | 28 | 1 | 0 | 38 | 119 |
| 2025 | 190 | 20 | 2 | 0 | 38 | 108 |
How does Huron County compare?
How Huron County compares
Good-day share better than US avg
Huron County 89.6%
Allegan County, Michigan 71.2%
US average 76.5%
Median AQI about average
Huron County 38
Allegan County, Michigan 43
US average 38
Unhealthy days / yr about average
Huron County 0
Allegan County, Michigan 1
US average 0
Other Counties in Michigan
Air quality comparison for nearby counties in Michigan.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Huron County.
Adams County, Illinois
AQI 38 · 94.4% good
Anoka County, Minnesota
AQI 38 · 82.1% good
Atlantic County, New Jersey
AQI 38 · 79.6% good
Avery County, North Carolina
AQI 38 · 93.9% good
Barnstable County, Massachusetts
AQI 38 · 92.5% good
Bay County, Michigan
AQI 38 · 71.8% good
What Huron County's air means for you
The air here stays in the breathable range year-round, with Ozone the main thing to watch.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-Ozone days, the guide explains what a median of 38 means for exposure. Health guidance
- See how Huron County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Huron County with its Michigan neighbours before drawing a conclusion about the region. All of Michigan
Based on 212 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
More Air Quality Data
Air Quality Guides
Frequently Asked Questions
What is the air quality in Huron County, Michigan? ▼
Huron County has a median Air Quality Index (AQI) of 38, rated "Good." 89.6% of monitored days (190 out of 212) had good air quality in 2025.
What is the main pollutant in Huron County? ▼
The primary pollutant in Huron County is Ozone (O3), which was the main AQI driver on 212 days (100% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Huron County have? ▼
In 2025, Huron County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 108.
Is the air quality in Huron County getting better or worse? ▼
Air quality in Huron County is stable based on 5-year trends (2020-2025). Best year: 2020 with 246 good days. Worst year: 2025 with 190 good days.
What does AQI 38 mean for health? ▼
Huron County's median AQI of 38 falls in the "Good" category. See the <a href="/guides/understanding-aqi" class="underline">AQI category guide</a> for what each range means for health.
How does Huron County compare to other counties in Michigan? ▼
Huron County has 89.6% good air days. Nearby counties in Michigan: Allegan (71.2% good), Bay (71.8% good), Benzie (91.1% good), Berrien (80.9% good), Cass (85.3% good), Clinton (90.2% good).
What is the 90th percentile AQI in Huron County? ▼
The 90th percentile AQI for Huron County is 51, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 108 (USG).
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.
Every figure on PlainAir 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.