Air quality reference

Bristol County, Massachusetts

US | 45 | Good | 2026-02-28T00:00:00+00:00

340National Rank
1,261National Count
45.0AQI
73.1National Percentile
1,042Category Observations
1Country Count
5Category Peers Count

Key facts

Location
Bristol County, Massachusetts
Air quality index
45
Category
Good
Defining parameter
Ozone
Sites reporting
1
Measured at
2026-02-28T00:00:00+00:00
Measurement context
Daily AQI summary from U.S. EPA AirData; values are not direct pollutant concentrations

Historical air-quality context

Published EPA annual CBSA indicators

Annual AQI summaries are shown independently from pollutant concentrations. Current-year values are provisional because reporting is incomplete and can be revised.

Annual indicator

Days with published AQI

59.00 days2026

EPA annual county summary field: Days with AQI. Current-year values are provisional. Values retain the source period and unit.

View source data
PerioddaysSource flagConfidentiality
202659.00 daysprovisional-current-year—

Annual indicator

Good AQI days

49.00 days2026

EPA annual county summary field: Good Days. Current-year values are provisional. Values retain the source period and unit.

View source data
PerioddaysSource flagConfidentiality
202649.00 daysprovisional-current-year—

Annual indicator

Hazardous AQI days

0.00 days2026

EPA annual county summary field: Hazardous Days. Current-year values are provisional. Values retain the source period and unit.

View source data
PerioddaysSource flagConfidentiality
20260.00 daysprovisional-current-year—

Annual indicator

Maximum daily AQI

69.00 AQI index2026

EPA annual county summary field: Max AQI. Current-year values are provisional. Values retain the source period and unit.

View source data
PeriodAQI indexSource flagConfidentiality
202669.00 AQI indexprovisional-current-year—

Annual indicator

Median daily AQI

37.00 AQI index2026

EPA annual county summary field: Median AQI. Current-year values are provisional. Values retain the source period and unit.

View source data
PeriodAQI indexSource flagConfidentiality
202637.00 AQI indexprovisional-current-year—

Annual indicator

Moderate AQI days

10.00 days2026

EPA annual county summary field: Moderate Days. Current-year values are provisional. Values retain the source period and unit.

View source data
PerioddaysSource flagConfidentiality
202610.00 daysprovisional-current-year—

Annual indicator

90th percentile daily AQI

57.00 AQI index2026

EPA annual county summary field: 90th Percentile AQI. Current-year values are provisional. Values retain the source period and unit.

View source data
PeriodAQI indexSource flagConfidentiality
202657.00 AQI indexprovisional-current-year—

Annual indicator

Unhealthy AQI days

0.00 days2026

EPA annual county summary field: Unhealthy Days. Current-year values are provisional. Values retain the source period and unit.

View source data
PerioddaysSource flagConfidentiality
20260.00 daysprovisional-current-year—

Annual indicator

Unhealthy for sensitive groups days

0.00 days2026

EPA annual county summary field: Unhealthy for Sensitive Groups Days. Current-year values are provisional. Values retain the source period and unit.

View source data
PerioddaysSource flagConfidentiality
20260.00 daysprovisional-current-year—

Annual indicator

Very unhealthy AQI days

0.00 days2026

EPA annual county summary field: Very Unhealthy Days. Current-year values are provisional. Values retain the source period and unit.

View source data
PerioddaysSource flagConfidentiality
20260.00 daysprovisional-current-year—

Field-level provenance

Sources for this profile

Dates and licenses apply to the specific facts and series supplied by each source.

Reference data can change. Verify consequential decisions against the original source.