Data / Highest daily Air Quality Index (US EPA) / Northampton County

Highest daily Air Quality Index (US EPA) in Northampton County

Highest daily Air Quality Index (US EPA) in Northampton County was 207 in 1990, according to the U.S. Environmental Protection Agency. That is up 48 from 1989.

1990, index207
Change on 1989+48
Series high2161983
Series low1591989

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Highest daily Air Quality Index (US EPA) in Northampton County, 1980 to 1990

1401601802002201980198219841986198819901980: 202 index1981: 214 index1982: 203 index1983: 216 index1984: 177 index1985: 200 index1986: 182 index1987: 197 index1988: 203 index1989: 159 index1990: 207 index1401601802002201980198419901980: 202 index1981: 214 index1982: 203 index1983: 216 index1984: 177 index1985: 200 index1986: 182 index1987: 197 index1988: 203 index1989: 159 index1990: 207 index
index. Source: EPA, EPA AirData annual AQI by county: highest daily AQI. Retrieved 2026-10-12, published 2026-07-13.
All 11 values
Periodindex
1990207
1989159
1988203
1987197
1986182
1985200
1984177
1983216
1982203
1981214
1980202

Northampton County compared with nearby places

Amherst County: 151 indexArlington County: 208 indexAugusta County: 151 indexBuchanan County: 78 indexCampbell County: 40 indexCarroll County: 53 indexCharles City County: 202 indexChesterfield County: 187 indexFairfax County: 212 indexFauquier County: 164 indexGiles County: 161 indexHanover County: 159 indexHenrico County: 200 indexKing William County: 52 indexLoudoun County: 57 indexMadison County: 169 indexNorthampton County: 207 indexPrince Edward County: 172 indexPrince William County: 41 indexRoanoke County: 129 indexSmyth County: 53 indexWarren County: 159 indexWythe County: 164 indexYork County: 53 indexAlexandria city: 185 indexBristol city: 55 indexCharlottesville city: 60 indexChesapeake city: 49 indexCovington city: 59 indexFairfax city: 200 indexFredericksburg city: 61 indexHampton city: 159 indexHopewell city: 59 indexLynchburg city: 49 indexMartinsville city: 45 indexNewport News city: 45 indexNorfolk city: 82 indexPortsmouth city: 52 indexRichmond city: 102 indexRoanoke city: 62 indexSuffolk city: 182 indexWinchester city: 61 index
  • Under 52
  • 52 to 59
  • 59 to 92
  • 92 to 160
  • 160 to 190
  • 190 and over
  • No data
Highest daily Air Quality Index (US EPA), 1990, index. Northampton County is outlined. Same source and period for every area shown. Source: U.S. Environmental Protection Agency. Boundaries: U.S. Census Bureau cartographic boundary files.

Rankings

Definition

Highest daily Air Quality Index (AQI) value recorded in a US county during the year, from the EPA AirData annual summaries. Values above 500 are beyond the AQI scale and are published as EPA computes them.

A single day decides the value, so one wildfire or dust event can set it. Dust from the dry Owens Lake bed puts Inyo and Mono counties in California in the thousands. United States counties with air quality monitors only, about 1,000 of some 3,100 in recent years; a county without monitors has no value. The number of days with an AQI differs between counties because some monitors run only in the ozone season.

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How to cite

U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: highest daily AQI. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

U.S. Environmental Protection Agency. (2026). EPA AirData annual AQI by county: highest daily AQI (Highest daily Air Quality Index (US EPA), Northampton County, 1980 to 1990) [Data set]. Retrieved October 12, 2026, from https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual

MLA 9

EPA AirData annual AQI by county: highest daily AQI, Highest daily Air Quality Index (US EPA), Northampton County, 1980 to 1990. U.S. Environmental Protection Agency, 13 July 2026, https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Invokely, https://invokely.ai/en/highest-daily-air-quality-index/northampton-county-virginia. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Environmental Protection Agency. 2026. EPA AirData annual AQI by county: highest daily AQI. Highest daily Air Quality Index (US EPA), Northampton County, 1980 to 1990. Dataset. Accessed October 12, 2026. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Also distributed by Invokely, https://invokely.ai/en/highest-daily-air-quality-index/northampton-county-virginia.

Harvard

U.S. Environmental Protection Agency (2026) EPA AirData annual AQI by county: highest daily AQI, Highest daily Air Quality Index (US EPA), Northampton County, 1980 to 1990 [Dataset]. Available at: https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual, via Invokely: https://invokely.ai/en/highest-daily-air-quality-index/northampton-county-virginia (Accessed: 12 October 2026).

BibTeX
@misc{environmental_highest_daily_air_quality_1990,
  author = {{U.S. Environmental Protection Agency}},
  title = {{EPA AirData annual AQI by county: highest daily AQI: Highest daily Air Quality Index (US EPA), Northampton County, 1980 to 1990}},
  year = {2026},
  howpublished = {Data set},
  url = {https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/en/highest-daily-air-quality-index/northampton-county-virginia. Publisher attribution: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: highest daily AQI. https://aqs.epa.gov/aqsweb/airdata/download\_files.html\#Annual. Retrieved 2026-10-12.},
}
RIS
TY  - DATA
AU  - U.S. Environmental Protection Agency
TI  - EPA AirData annual AQI by county: highest daily AQI: Highest daily Air Quality Index (US EPA), Northampton County, 1980 to 1990
PY  - 2026
DA  - 2026/07/13
PB  - U.S. Environmental Protection Agency
DB  - Invokely
UR  - https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual
L2  - https://invokely.ai/en/highest-daily-air-quality-index/northampton-county-virginia
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/en/highest-daily-air-quality-index/northampton-county-virginia.
N1  - Publisher attribution: U.S. Environmental Protection Agency, Air Quality System, AirData. EPA AirData annual AQI by county: highest daily AQI. https://aqs.epa.gov/aqsweb/airdata/download_files.html#Annual. Retrieved 2026-10-12.
ER  -
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Questions

What is the highest daily Air Quality Index (US EPA) in Northampton County?

Highest daily Air Quality Index (US EPA) in Northampton County was 207 in 1990, according to the U.S. Environmental Protection Agency. That is up 48 from 1989.

Where does this figure come from?

U.S. Environmental Protection Agency. EPA AirData annual AQI by county: highest daily AQI. Retrieved by Invokely on 2026-10-12.

What was the highest highest daily Air Quality Index (US EPA) in Northampton County?

216 in 1983, the highest value since 1980 in this series.

Related statistics for Northampton County

All statistics for Northampton County | Northampton County in figures