Median AQI
39
Good
West Virginia · County air quality · 2025
Wood County, West Virginia
Median AQI 39 (Good). 83.5% of monitored days rated Good, direct from EPA Air Quality System stations.
- 39
- Median AQI
- 83.5%
- Good-air days
- 0
- Unhealthy days
- 61%
- Cleaner than US counties
The verdict
According to EPA Air Quality System monitoring data, Wood County's air is good on balance, cleaner than the median US county, a median AQI of 39 with 83.5% of 139 monitored days in the Good band, driven mainly by Ozone.
- 39
- median AQI · Good
- 83.5%
- days rated Good
- Ozone
- main pollutant
- 61%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 77.
Data updated July 2026
- Good · 116 d · 83.5%
- Moderate · 23 d · 16.5%
How did Wood County's air break down in 2025?
Across 139 monitored days, 116 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 77 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 139 days monitored. Median AQI: 39 (Good).
Insights: Wood County, West Virginia. EPA monitors recorded a median Air Quality Index of 39 across 139 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 116 (83%) fell in the Good band (AQI 0–50), 23 (17%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 55, while the worst single-day peak hit 77 (Moderate). Residents averaged about 25.0 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (106 days), PM2.5 (33 days). Across the 2020–2025 trend window, good days shifted by -134 and the median AQI moved +2 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 77, moderate but never Unhealthy. Nearby counties show comparable readings: Berkeley (81.1% good, AQI 40); Brooke (79.3% good, AQI 35); Cabell (74.0% good, AQI 41); Greenbrier (89.3% good, AQI 42); Hancock (74.6% good, AQI 42); Harrison (73.3% good, AQI 32).
Air Quality Summary
Good Days
83.5%
116 of 139 monitored days
8.5pp vs 75% target
Max AQI Recorded
77
Moderate
Health Grade
Good
90th-pct AQI 55
Wood County, Good days share 83.5%
National avg
Share of monitored days at AQI 0-50 (Good band).
Wood 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 139 monitored days across EPA AQI categories.
Good
116
83%
Moderate
23
17%
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 Wood County.
- Ozone · 106 days · 76.3%
- PM2.5 · 33 days · 23.7%
Health Impact Assessment
Good
Wood County's air quality is rated Good based on 83.5% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 83.5% of monitored days in 2025, with a median AQI of 39. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is Ozone, driving AQI on 106 of 139 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Wood County. Best year: 2020 (250 good days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 250 | 33 | 0 | 0 | 37 | 80 |
| 2021 | 221 | 50 | 0 | 0 | 38 | 76 |
| 2022 | 242 | 38 | 1 | 0 | 39 | 108 |
| 2023 | 213 | 53 | 2 | 1 | 41 | 166 |
| 2024 | 219 | 60 | 1 | 0 | 43 | 101 |
| 2025 | 116 | 23 | 0 | 0 | 39 | 77 |
How does Wood County compare?
How Wood County compares
Good-day share better than US avg
Wood County 83.5%
Berkeley County, West Virginia 81.1%
US average 76.5%
Median AQI worse than US avg
Wood County 39
Berkeley County, West Virginia 40
US average 38
Unhealthy days / yr about average
Wood County 0
Berkeley County, West Virginia 0
US average 0
Other Counties in West Virginia
Air quality comparison for nearby counties in West Virginia.
Counties with Similar Air Quality
Counties across the US with a similar median AQI to Wood County.
Ada County, Idaho
AQI 39 · 80.6% good
Aiken County, South Carolina
AQI 39 · 89.1% good
Albany County, New York
AQI 39 · 67.4% good
Alexander County, North Carolina
AQI 39 · 92.4% good
Ashland County, Wisconsin
AQI 39 · 85.6% good
Bennington County, Vermont
AQI 39 · 82.9% good
What Wood 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 39 means for exposure. Health guidance
- See how Wood County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Wood County with its West Virginia neighbours before drawing a conclusion about the region. All of West Virginia
Based on 139 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 Wood County, West Virginia? ▼
Wood County has a median Air Quality Index (AQI) of 39, rated "Good." 83.5% of monitored days (116 out of 139) had good air quality in 2025.
What is the main pollutant in Wood County? ▼
The primary pollutant in Wood County is Ozone (O3), which was the main AQI driver on 106 days (76% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Wood County have? ▼
In 2025, Wood County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 77.
Is the air quality in Wood County getting better or worse? ▼
Air quality in Wood County is worsening based on 5-year trends (2020-2025). Best year: 2020 with 250 good days. Worst year: 2025 with 116 good days.
What does AQI 39 mean for health? ▼
Wood County's median AQI of 39 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 Wood County compare to other counties in West Virginia? ▼
Wood County has 83.5% good air days. Nearby counties in West Virginia: Berkeley (81.1% good), Brooke (79.3% good), Cabell (74.0% good), Greenbrier (89.3% good), Hancock (74.6% good), Harrison (73.3% good).
What is the 90th percentile AQI in Wood County? ▼
The 90th percentile AQI for Wood County is 55, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 77 (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.