Median AQI
34
Good
Minnesota · County air quality · 2025
Lake County, Minnesota
Median AQI 34 (Good). 95.7% of monitored days rated Good, direct from EPA Air Quality System stations.
- 34
- Median AQI
- 95.7%
- Good-air days
- 0
- Unhealthy days
- 91%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Lake County's air is good on balance, among the cleanest 10% of US counties, a median AQI of 34 with 95.7% of 162 monitored days in the Good band, driven mainly by Ozone.
- 34
- median AQI · Good
- 95.7%
- days rated Good
- Ozone
- main pollutant
- 91%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 129.
Data updated July 2026
- Good · 155 d · 95.7%
- Moderate · 4 d · 2.5%
- USG · 3 d · 1.9%
How did Lake County's air break down in 2025?
Across 162 monitored days, 155 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 129 (USG).
EPA AQS →Air quality data from EPA Air Quality System (2025). 162 days monitored. Median AQI: 34 (Good).
Insights: Lake County, Minnesota. EPA monitors recorded a median Air Quality Index of 34 across 162 measured days in 2025, earning a Good classification and a Excellent health grade. Of those days, 155 (96%) fell in the Good band (AQI 0–50), 4 (2%) registered Moderate readings, and 3 (2%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 46, while the worst single-day peak hit 129 (USG). Residents averaged about 28.7 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (98 days), PM2.5 (64 days). Across the 2020–2025 trend window, good days shifted by -189 and the median AQI moved +0 points, placing the multi-year trajectory at stable. The worst single reading over the 2020–2025 window was AQI 129, usg but never Unhealthy. Nearby counties show comparable readings: Anoka (82.1% good, AQI 38); Becker (84.7% good, AQI 38); Beltrami (88.8% good, AQI 37); Blue Earth (82.7% good, AQI 38); Carlton (92.9% good, AQI 35); Cass (94.4% good, AQI 22).
Air Quality Summary
Good Days
95.7%
155 of 162 monitored days
20.7pp vs 75% target
Max AQI Recorded
129
USG
Health Grade
Excellent
90th-pct AQI 46
Lake County, Good days share 95.7%
National avg
Share of monitored days at AQI 0-50 (Good band).
Lake 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 162 monitored days across EPA AQI categories.
Good
155
96%
Moderate
4
2%
USG
3
2%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Lake County.
- Ozone · 98 days · 60.5%
- PM2.5 · 64 days · 39.5%
Health Impact Assessment
Excellent
Lake County's air quality is rated Excellent based on 95.7% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 95.7% of monitored days in 2025, with a median AQI of 34. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is Ozone, driving AQI on 98 of 162 monitored days.
5-Year Air Quality Trend
Air quality is stable in Lake County. Best year: 2020 (344 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 344 | 21 | 0 | 0 | 34 | 71 |
| 2021 | 315 | 43 | 3 | 1 | 31 | 160 |
| 2022 | 342 | 15 | 0 | 0 | 31 | 78 |
| 2023 | 282 | 81 | 2 | 0 | 36 | 114 |
| 2024 | 330 | 35 | 1 | 0 | 32 | 110 |
| 2025 | 155 | 4 | 3 | 0 | 34 | 129 |
How does Lake County compare?
How Lake County compares
Good-day share better than US avg
Lake County 95.7%
Anoka County, Minnesota 82.1%
US average 76.5%
Median AQI better than US avg
Lake County 34
Anoka County, Minnesota 38
US average 38
Unhealthy days / yr about average
Lake County 0
Anoka County, Minnesota 1
US average 0
Other Counties in Minnesota
Air quality comparison for nearby counties in Minnesota.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Lake County.
Belknap County, New Hampshire
AQI 34 · 87.9% good
Dyer County, Tennessee
AQI 34 · 79.4% good
Flagler County, Florida
AQI 34 · 97.4% good
Grant County, Oregon
AQI 34 · 66.7% good
Highlands County, Florida
AQI 34 · 93.2% good
Johnson County, Texas
AQI 34 · 91.6% good
What Lake 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 34 means for exposure. Health guidance
- See how Lake County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Lake County with its Minnesota neighbours before drawing a conclusion about the region. All of Minnesota
Based on 162 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 Lake County, Minnesota? ▼
Lake County has a median Air Quality Index (AQI) of 34, rated "Good." 95.7% of monitored days (155 out of 162) had good air quality in 2025.
What is the main pollutant in Lake County? ▼
The primary pollutant in Lake County is Ozone (O3), which was the main AQI driver on 98 days (60% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Lake County have? ▼
In 2025, Lake County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 129.
Is the air quality in Lake County getting better or worse? ▼
Air quality in Lake County is stable based on 5-year trends (2020-2025). Best year: 2020 with 344 good days. Worst year: 2025 with 155 good days.
What does AQI 34 mean for health? ▼
Lake County's median AQI of 34 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 Lake County compare to other counties in Minnesota? ▼
Lake County has 95.7% good air days. Nearby counties in Minnesota: Anoka (82.1% good), Becker (84.7% good), Beltrami (88.8% good), Blue Earth (82.7% good), Carlton (92.9% good), Cass (94.4% good).
What is the 90th percentile AQI in Lake County? ▼
The 90th percentile AQI for Lake County is 46, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 129 (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.