EnviroNearby

Berkeley County, West Virginia air quality history

Daily Air Quality Index summaries from EPA monitors in Berkeley, West Virginia, 1999–2025.

84%
Good days in 2025
39
Median daily AQI, 2025
0
Days above 100 in 2025
269
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Berkeley, West Virginia on 269 days. 225 of those days (84%) were in the Good range, and the median daily AQI was 39. That median is about the same as the typical monitored county in West Virginia (median 39 across 12 counties), and about the same as the typical monitored U.S. county (40). The main pollutant was ozone on 193 days. Across the years with fuller monitoring, the share of Good days rose: an average of 46% in 2001–2003 versus 79% in 2023–2025.

EPA did not report an AQI for every day of 2025 here (269 of 365 days). Figures describe monitored days only; seasonal monitoring (for example, ozone measured only in warmer months) can make a county look cleaner or dirtier than a full-year record would.

Years with fewer than 120 monitored days (1999, 2000) are shown in the table but left out of comparisons and trend statements.

How the days broke down each year

Each bar is one year. The colored segments show the share of monitored days that fell in each AQI category.

Share of monitored days in each AQI category, by year0%25%50%75%100%1999: Good 28 of 99 days1999: Moderate 67 of 99 days1999: Unhealthy for Sensitive Groups 4 of 99 days19992000: Good 28 of 113 days2000: Moderate 80 of 113 days2000: Unhealthy for Sensitive Groups 5 of 113 days2001: Good 105 of 252 days2001: Moderate 126 of 252 days2001: Unhealthy for Sensitive Groups 15 of 252 days2001: Unhealthy 6 of 252 days20012002: Good 120 of 260 days2002: Moderate 107 of 260 days2002: Unhealthy for Sensitive Groups 27 of 260 days2002: Unhealthy 6 of 260 days2003: Good 132 of 262 days2003: Moderate 119 of 262 days2003: Unhealthy for Sensitive Groups 8 of 262 days2003: Unhealthy 3 of 262 days20032004: Good 145 of 260 days2004: Moderate 110 of 260 days2004: Unhealthy for Sensitive Groups 4 of 260 days2004: Unhealthy 1 of 260 days2005: Good 122 of 264 days2005: Moderate 125 of 264 days2005: Unhealthy for Sensitive Groups 16 of 264 days2005: Unhealthy 1 of 264 days20052006: Good 140 of 264 days2006: Moderate 112 of 264 days2006: Unhealthy for Sensitive Groups 11 of 264 days2006: Unhealthy 1 of 264 days2007: Good 118 of 256 days2007: Moderate 125 of 256 days2007: Unhealthy for Sensitive Groups 12 of 256 days2007: Unhealthy 1 of 256 days20072008: Good 143 of 259 days2008: Moderate 109 of 259 days2008: Unhealthy for Sensitive Groups 7 of 259 days2009: Good 168 of 263 days2009: Moderate 95 of 263 days20092010: Good 128 of 258 days2010: Moderate 117 of 258 days2010: Unhealthy for Sensitive Groups 12 of 258 days2010: Unhealthy 1 of 258 days2011: Good 171 of 263 days2011: Moderate 91 of 263 days2011: Unhealthy for Sensitive Groups 1 of 263 days20112012: Good 147 of 254 days2012: Moderate 106 of 254 days2012: Unhealthy for Sensitive Groups 1 of 254 days2013: Good 188 of 263 days2013: Moderate 74 of 263 days2013: Unhealthy for Sensitive Groups 1 of 263 days20132014: Good 178 of 250 days2014: Moderate 72 of 250 days2015: Good 162 of 254 days2015: Moderate 92 of 254 days20152016: Good 186 of 255 days2016: Moderate 68 of 255 days2016: Unhealthy for Sensitive Groups 1 of 255 days2017: Good 226 of 285 days2017: Moderate 59 of 285 days20172018: Good 229 of 281 days2018: Moderate 52 of 281 days2019: Good 233 of 278 days2019: Moderate 43 of 278 days2019: Unhealthy for Sensitive Groups 2 of 278 days20192020: Good 244 of 278 days2020: Moderate 34 of 278 days2021: Good 214 of 273 days2021: Moderate 59 of 273 days20212022: Good 230 of 275 days2022: Moderate 45 of 275 days2023: Good 206 of 277 days2023: Moderate 66 of 277 days2023: Unhealthy for Sensitive Groups 4 of 277 days2023: Unhealthy 1 of 277 days20232024: Good 217 of 275 days2024: Moderate 58 of 275 days2025: Good 225 of 269 days2025: Moderate 44 of 269 days2025
  • Good
  • Moderate
  • Unhealthy for Sensitive Groups
  • Unhealthy
  • Very Unhealthy
  • Hazardous

Typical and high-end AQI over time

The median is the middle day of the year. The 90th percentile is the level that only the highest 10% of days exceeded.

Median and 90th-percentile daily AQI, by year0501001501999: 90th percentile AQI 952000: 90th percentile AQI 832001: 90th percentile AQI 972002: 90th percentile AQI 1092003: 90th percentile AQI 812004: 90th percentile AQI 812005: 90th percentile AQI 902006: 90th percentile AQI 852007: 90th percentile AQI 872008: 90th percentile AQI 762009: 90th percentile AQI 702010: 90th percentile AQI 822011: 90th percentile AQI 712012: 90th percentile AQI 742013: 90th percentile AQI 622014: 90th percentile AQI 612015: 90th percentile AQI 692016: 90th percentile AQI 632017: 90th percentile AQI 562018: 90th percentile AQI 562019: 90th percentile AQI 542020: 90th percentile AQI 522021: 90th percentile AQI 602022: 90th percentile AQI 542023: 90th percentile AQI 642024: 90th percentile AQI 612025: 90th percentile AQI 541999: Median AQI 602000: Median AQI 612001: Median AQI 572002: Median AQI 522003: Median AQI 502004: Median AQI 482005: Median AQI 542006: Median AQI 492007: Median AQI 522008: Median AQI 482009: Median AQI 452010: Median AQI 512011: Median AQI 462012: Median AQI 472013: Median AQI 432014: Median AQI 442015: Median AQI 472016: Median AQI 422017: Median AQI 402018: Median AQI 392019: Median AQI 402020: Median AQI 382021: Median AQI 402022: Median AQI 382023: Median AQI 442024: Median AQI 422025: Median AQI 3919992001200320052007200920112013201520172019202120232025
  • Median daily AQI
  • 90th-percentile daily AQI

Main pollutant by day, 2025

On each monitored day, the AQI reflects whichever measured pollutant had the highest index. This counts how many days each pollutant set the AQI. A pollutant that was not measured here cannot appear.

PollutantDays as main pollutantShare of monitored days
Ozone19372%
Fine particles (PM2.5)7628%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
2025269225440000395487Ozone
2024275217580000426197Ozone
20232772066641004464171Ozone
2022275230450000385488Ozone
2021273214590000406093Ozone
2020278244340000385295Ozone
20192782334320004054127Ozone
2018281229520000395688Ozone
2017285226590000405677Ozone
20162551866810004263112Ozone
20152541629200004769100Ozone
2014250178720000446191Ozone
20132631887410004362131Ozone
201225414710610004774140Ozone
20112631719110004671105Ozone
2010258128117121005182159Ozone
20092631689500004570100Ozone
200825914310970004876129Ozone
2007256118125121005287156Ozone
2006264140112111004985159Ozone
2005264122125161005490161Ozone
200426014511041004881161Ozone
200326213211983005081172Ozone
20022601201072760052109172Ozone
2001252105126156005797164Ozone
2000113288050006183132PM2.5
199999286740006095130PM2.5

What this data can and can’t tell you

It is a county-level summary. EPA reports one AQI per day for the county, based on the monitors operating there. Air at a particular street, school or home can differ, especially near roads, industry or wildfire smoke.

It is not a health assessment. The AQI is EPA’s scale for communicating daily air quality. A county’s history can’t tell you what the health risk is for any particular person. For daily conditions and health guidance, see AirNow.

Rules change over time. EPA has revised AQI breakpoints, most recently for fine particles in 2024, so some year-to-year change can reflect the scale rather than the air.

Counties in West Virginia with a similar median AQI in 2025

All monitored counties in West Virginia

Source: U.S. EPA AirData, “Annual AQI by County” files for 1999–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem