Median AQI
38
Good
Mississippi · County air quality · 2025
Lee County, Mississippi
Median AQI 38 (Good). 94.8% of monitored days rated Good, direct from EPA Air Quality System stations.
- 38
- Median AQI
- 94.8%
- Good-air days
- 0
- Unhealthy days
- 89%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Lee County's air is good on balance, cleaner than most US counties, a median AQI of 38 with 94.8% of 211 monitored days in the Good band, driven mainly by Ozone.
- 38
- median AQI · Good
- 94.8%
- days rated Good
- Ozone
- main pollutant
- 89%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 64.
Data updated July 2026
- Good · 200 d · 94.8%
- Moderate · 11 d · 5.2%
How did Lee County's air break down in 2025?
Across 211 monitored days, 200 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 64 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 211 days monitored. Median AQI: 38 (Good).
Insights: Lee County, Mississippi. EPA monitors recorded a median Air Quality Index of 38 across 211 measured days in 2025, earning a Good classification and a Excellent health grade. Of those days, 200 (95%) fell in the Good band (AQI 0–50), 11 (5%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 48, while the worst single-day peak hit 64 (Moderate). Residents averaged about 28.4 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (211 days). Across the 2020–2025 trend window, good days shifted by -42 and the median AQI moved +3 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 64, moderate but never Unhealthy. Nearby counties show comparable readings: Bolivar (70.3% good, AQI 44); DeSoto (67.0% good, AQI 44); Forrest (62.4% good, AQI 46); Hancock (67.8% good, AQI 44); Harrison (64.5% good, AQI 45); Hinds (43.4% good, AQI 52).
Air Quality Summary
Good Days
94.8%
200 of 211 monitored days
19.8pp vs 75% target
Max AQI Recorded
64
Moderate
Health Grade
Excellent
90th-pct AQI 48
Lee County, Good days share 94.8%
National avg
Share of monitored days at AQI 0-50 (Good band).
Lee 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 211 monitored days across EPA AQI categories.
Good
200
95%
Moderate
11
5%
USG
0
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Lee County.
- Ozone · 211 days · 100.0%
Health Impact Assessment
Excellent
Lee County's air quality is rated Excellent based on 94.8% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 94.8% 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 211 of 211 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Lee County. Best year: 2020 (242 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 242 | 1 | 0 | 0 | 35 | 54 |
| 2021 | 232 | 10 | 0 | 0 | 36 | 64 |
| 2022 | 225 | 19 | 0 | 0 | 40 | 100 |
| 2023 | 212 | 31 | 2 | 0 | 42 | 122 |
| 2024 | 216 | 27 | 0 | 0 | 41 | 87 |
| 2025 | 200 | 11 | 0 | 0 | 38 | 64 |
How does Lee County compare?
How Lee County compares
Good-day share better than US avg
Lee County 94.8%
Bolivar County, Mississippi 70.3%
US average 76.5%
Median AQI about average
Lee County 38
Bolivar County, Mississippi 44
US average 38
Unhealthy days / yr about average
Lee County 0
Bolivar County, Mississippi 0
US average 0
Other Counties in Mississippi
Air quality comparison for nearby counties in Mississippi.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Lee 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 Lee 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 Lee County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Lee County with its Mississippi neighbours before drawing a conclusion about the region. All of Mississippi
Based on 211 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 Lee County, Mississippi? ▼
Lee County has a median Air Quality Index (AQI) of 38, rated "Good." 94.8% of monitored days (200 out of 211) had good air quality in 2025.
What is the main pollutant in Lee County? ▼
The primary pollutant in Lee County is Ozone (O3), which was the main AQI driver on 211 days (100% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Lee County have? ▼
In 2025, Lee County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 64.
Is the air quality in Lee County getting better or worse? ▼
Air quality in Lee County is worsening based on 5-year trends (2020-2025). Best year: 2020 with 242 good days. Worst year: 2025 with 200 good days.
What does AQI 38 mean for health? ▼
Lee 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 Lee County compare to other counties in Mississippi? ▼
Lee County has 94.8% good air days. Nearby counties in Mississippi: Bolivar (70.3% good), DeSoto (67.0% good), Forrest (62.4% good), Hancock (67.8% good), Harrison (64.5% good), Hinds (43.4% good).
What is the 90th percentile AQI in Lee County? ▼
The 90th percentile AQI for Lee County is 48, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 64 (Moderate).
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.