EnviroNearby

Arlington County, Virginia air quality history

Daily Air Quality Index summaries from EPA monitors in Arlington, Virginia, 1980–2025.

87%
Good days in 2025
37
Median daily AQI, 2025
2
Days above 100 in 2025
365
Days with an AQI in 2025 (of 365)

In 2025, EPA reported a daily Air Quality Index (AQI) for Arlington, Virginia on 365 days. 319 of those days (87%) were in the Good range, and the median daily AQI was 37. That median is about the same as the typical monitored county in Virginia (median 37 across 25 counties), and lower than the typical monitored U.S. county (40). The main pollutant was ozone on 272 days. Across the years with fuller monitoring, the share of Good days rose: an average of 61% in 1980–1982 versus 85% in 2023–2025.

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%1980: Good 198 of 346 days1980: Moderate 99 of 346 days1980: Unhealthy for Sensitive Groups 32 of 346 days1980: Unhealthy 14 of 346 days1980: Very Unhealthy 3 of 346 days19801981: Good 224 of 360 days1981: Moderate 98 of 360 days1981: Unhealthy for Sensitive Groups 24 of 360 days1981: Unhealthy 13 of 360 days1981: Very Unhealthy 1 of 360 days1982: Good 227 of 363 days1982: Moderate 95 of 363 days1982: Unhealthy for Sensitive Groups 26 of 363 days1982: Unhealthy 13 of 363 days1982: Very Unhealthy 2 of 363 days1983: Good 216 of 365 days1983: Moderate 97 of 365 days1983: Unhealthy for Sensitive Groups 25 of 365 days1983: Unhealthy 21 of 365 days1983: Very Unhealthy 6 of 365 days1984: Good 198 of 366 days1984: Moderate 126 of 366 days1984: Unhealthy for Sensitive Groups 28 of 366 days1984: Unhealthy 12 of 366 days1984: Very Unhealthy 2 of 366 days1985: Good 208 of 365 days1985: Moderate 102 of 365 days1985: Unhealthy for Sensitive Groups 44 of 365 days1985: Unhealthy 10 of 365 days1985: Very Unhealthy 1 of 365 days19851986: Good 206 of 364 days1986: Moderate 116 of 364 days1986: Unhealthy for Sensitive Groups 26 of 364 days1986: Unhealthy 16 of 364 days1987: Good 186 of 365 days1987: Moderate 132 of 365 days1987: Unhealthy for Sensitive Groups 29 of 365 days1987: Unhealthy 18 of 365 days1988: Good 237 of 366 days1988: Moderate 65 of 366 days1988: Unhealthy for Sensitive Groups 30 of 366 days1988: Unhealthy 17 of 366 days1988: Very Unhealthy 17 of 366 days1989: Good 235 of 365 days1989: Moderate 102 of 365 days1989: Unhealthy for Sensitive Groups 23 of 365 days1989: Unhealthy 5 of 365 days1990: Good 223 of 365 days1990: Moderate 104 of 365 days1990: Unhealthy for Sensitive Groups 32 of 365 days1990: Unhealthy 5 of 365 days1990: Very Unhealthy 1 of 365 days19901991: Good 213 of 365 days1991: Moderate 101 of 365 days1991: Unhealthy for Sensitive Groups 33 of 365 days1991: Unhealthy 17 of 365 days1991: Very Unhealthy 1 of 365 days1992: Good 248 of 366 days1992: Moderate 90 of 366 days1992: Unhealthy for Sensitive Groups 25 of 366 days1992: Unhealthy 3 of 366 days1993: Good 212 of 364 days1993: Moderate 106 of 364 days1993: Unhealthy for Sensitive Groups 34 of 364 days1993: Unhealthy 11 of 364 days1993: Very Unhealthy 1 of 364 days1994: Good 230 of 365 days1994: Moderate 95 of 365 days1994: Unhealthy for Sensitive Groups 32 of 365 days1994: Unhealthy 7 of 365 days1994: Very Unhealthy 1 of 365 days1995: Good 238 of 365 days1995: Moderate 88 of 365 days1995: Unhealthy for Sensitive Groups 24 of 365 days1995: Unhealthy 14 of 365 days1995: Very Unhealthy 1 of 365 days19951996: Good 243 of 366 days1996: Moderate 98 of 366 days1996: Unhealthy for Sensitive Groups 24 of 366 days1996: Unhealthy 1 of 366 days1997: Good 173 of 280 days1997: Moderate 67 of 280 days1997: Unhealthy for Sensitive Groups 23 of 280 days1997: Unhealthy 14 of 280 days1997: Very Unhealthy 3 of 280 days1998: Good 213 of 341 days1998: Moderate 90 of 341 days1998: Unhealthy for Sensitive Groups 28 of 341 days1998: Unhealthy 10 of 341 days1999: Good 202 of 365 days1999: Moderate 113 of 365 days1999: Unhealthy for Sensitive Groups 31 of 365 days1999: Unhealthy 19 of 365 days2000: Good 213 of 366 days2000: Moderate 137 of 366 days2000: Unhealthy for Sensitive Groups 13 of 366 days2000: Unhealthy 3 of 366 days20002001: Good 201 of 365 days2001: Moderate 136 of 365 days2001: Unhealthy for Sensitive Groups 17 of 365 days2001: Unhealthy 11 of 365 days2002: Good 195 of 365 days2002: Moderate 125 of 365 days2002: Unhealthy for Sensitive Groups 28 of 365 days2002: Unhealthy 12 of 365 days2002: Very Unhealthy 5 of 365 days2003: Good 205 of 363 days2003: Moderate 141 of 363 days2003: Unhealthy for Sensitive Groups 13 of 363 days2003: Unhealthy 2 of 363 days2003: Very Unhealthy 2 of 363 days2004: Good 212 of 366 days2004: Moderate 134 of 366 days2004: Unhealthy for Sensitive Groups 16 of 366 days2004: Unhealthy 4 of 366 days2005: Good 215 of 365 days2005: Moderate 123 of 365 days2005: Unhealthy for Sensitive Groups 22 of 365 days2005: Unhealthy 5 of 365 days20052006: Good 222 of 365 days2006: Moderate 115 of 365 days2006: Unhealthy for Sensitive Groups 25 of 365 days2006: Unhealthy 3 of 365 days2007: Good 201 of 365 days2007: Moderate 133 of 365 days2007: Unhealthy for Sensitive Groups 26 of 365 days2007: Unhealthy 5 of 365 days2008: Good 238 of 366 days2008: Moderate 116 of 366 days2008: Unhealthy for Sensitive Groups 9 of 366 days2008: Unhealthy 3 of 366 days2009: Good 277 of 365 days2009: Moderate 85 of 365 days2009: Unhealthy for Sensitive Groups 3 of 365 days2010: Good 241 of 365 days2010: Moderate 97 of 365 days2010: Unhealthy for Sensitive Groups 23 of 365 days2010: Unhealthy 4 of 365 days20102011: Good 265 of 365 days2011: Moderate 81 of 365 days2011: Unhealthy for Sensitive Groups 15 of 365 days2011: Unhealthy 4 of 365 days2012: Good 260 of 366 days2012: Moderate 88 of 366 days2012: Unhealthy for Sensitive Groups 15 of 366 days2012: Unhealthy 3 of 366 days2013: Good 275 of 365 days2013: Moderate 89 of 365 days2013: Unhealthy for Sensitive Groups 1 of 365 days2014: Good 290 of 365 days2014: Moderate 70 of 365 days2014: Unhealthy for Sensitive Groups 4 of 365 days2014: Unhealthy 1 of 365 days2015: Good 271 of 365 days2015: Moderate 88 of 365 days2015: Unhealthy for Sensitive Groups 6 of 365 days20152016: Good 285 of 366 days2016: Moderate 74 of 366 days2016: Unhealthy for Sensitive Groups 7 of 366 days2017: Good 297 of 365 days2017: Moderate 65 of 365 days2017: Unhealthy for Sensitive Groups 3 of 365 days2018: Good 298 of 365 days2018: Moderate 64 of 365 days2018: Unhealthy for Sensitive Groups 3 of 365 days2019: Good 294 of 365 days2019: Moderate 70 of 365 days2019: Unhealthy for Sensitive Groups 1 of 365 days2020: Good 332 of 366 days2020: Moderate 34 of 366 days20202021: Good 306 of 365 days2021: Moderate 56 of 365 days2021: Unhealthy for Sensitive Groups 3 of 365 days2022: Good 325 of 365 days2022: Moderate 40 of 365 days2023: Good 302 of 365 days2023: Moderate 58 of 365 days2023: Unhealthy for Sensitive Groups 3 of 365 days2023: Unhealthy 2 of 365 days2024: Good 309 of 366 days2024: Moderate 53 of 366 days2024: Unhealthy for Sensitive Groups 4 of 366 days2025: Good 319 of 365 days2025: Moderate 44 of 365 days2025: Unhealthy for Sensitive Groups 2 of 365 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 year0501001501980: 90th percentile AQI 1191981: 90th percentile AQI 1051982: 90th percentile AQI 1051983: 90th percentile AQI 1191984: 90th percentile AQI 1031985: 90th percentile AQI 1081986: 90th percentile AQI 1051987: 90th percentile AQI 1151988: 90th percentile AQI 1431989: 90th percentile AQI 891990: 90th percentile AQI 1011991: 90th percentile AQI 1221992: 90th percentile AQI 871993: 90th percentile AQI 1081994: 90th percentile AQI 1011995: 90th percentile AQI 1011996: 90th percentile AQI 871997: 90th percentile AQI 1151998: 90th percentile AQI 1121999: 90th percentile AQI 1152000: 90th percentile AQI 842001: 90th percentile AQI 962002: 90th percentile AQI 1152003: 90th percentile AQI 822004: 90th percentile AQI 842005: 90th percentile AQI 902006: 90th percentile AQI 932007: 90th percentile AQI 972008: 90th percentile AQI 772009: 90th percentile AQI 622010: 90th percentile AQI 902011: 90th percentile AQI 842012: 90th percentile AQI 772013: 90th percentile AQI 632014: 90th percentile AQI 602015: 90th percentile AQI 672016: 90th percentile AQI 672017: 90th percentile AQI 582018: 90th percentile AQI 622019: 90th percentile AQI 612020: 90th percentile AQI 492021: 90th percentile AQI 552022: 90th percentile AQI 512023: 90th percentile AQI 582024: 90th percentile AQI 562025: 90th percentile AQI 541980: Median AQI 471981: Median AQI 421982: Median AQI 421983: Median AQI 431984: Median AQI 471985: Median AQI 421986: Median AQI 471987: Median AQI 471988: Median AQI 421989: Median AQI 441990: Median AQI 451991: Median AQI 471992: Median AQI 421993: Median AQI 471994: Median AQI 451995: Median AQI 411996: Median AQI 431997: Median AQI 451998: Median AQI 451999: Median AQI 482000: Median AQI 462001: Median AQI 492002: Median AQI 472003: Median AQI 482004: Median AQI 462005: Median AQI 452006: Median AQI 452007: Median AQI 472008: Median AQI 422009: Median AQI 392010: Median AQI 432011: Median AQI 382012: Median AQI 392013: Median AQI 392014: Median AQI 412015: Median AQI 412016: Median AQI 382017: Median AQI 392018: Median AQI 362019: Median AQI 402020: Median AQI 342021: Median AQI 382022: Median AQI 372023: Median AQI 382024: Median AQI 362025: Median AQI 371980198519901995200020052010201520202025
  • 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
Ozone27275%
Fine particles (PM2.5)4713%
Nitrogen dioxide (NO₂)4613%

Year-by-year data

Annual AQI summary by year
YearDays with AQIGoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardousMedian AQI90th pct.Max AQIMain pollutant
20253653194420003754140Ozone
20243663095340003656115Ozone
20233653025832003858181Ozone
20223653254000003751100Ozone
20213653065630003855115Ozone
2020366332340000344990Ozone
20193652947010004061112Ozone
20183652986430003662122Ozone
20173652976530003958115Ozone
20163662857470003867133Ozone
20153652718860004167126Ozone
20143652907041004160154Ozone
20133652758910003963115Ozone
201236626088153003977172Ozone
201136526581154003884187Ozone
201036524197234004390166Ozone
20093652778530003962126Ozone
200836623811693004277197Ozone
2007365201133265004797174Ozone
2006365222115253004593190Ozone
2005365215123225004590172NO2
2004366212134164004684190NO2
2003363205141132204882210NO2
200236519512528125047115229NO2
20013652011361711004996195NO2
2000366213137133004684182NO2
199936520211331190048115200NO2
19983412139028100045112185NO2
19972801736723143045115221NO2
199636624398241004387151NO2
19953652388824141041101213NO2
1994365230953271045101205NO2
199336421210634111047108203NO2
199236624890253004287177NO2
199136521310133171047122224NO2
19903652231043251045101208NO2
1989365235102235004489190NO2
198836623765301717042143245Ozone
198736518613229180047115200NO2
198636420611626160047105200NO2
198536520810244101042108206NO2
198436619812628122047103206NO2
19833652169725216043119233NO2
19823632279526132042105213NO2
19813602249824131042105213NO2
19803461989932143047119227NO2

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 Virginia with a similar median AQI in 2025

All monitored counties in Virginia

Source: U.S. EPA AirData, “Annual AQI by County” files for 1980–2025 (EPA download page). EPA file dates: 2026-06-26. Imported into EnviroNearby November 5, 2026. How we use this data · Report a problem