Metro area air quality · 2024

Barnstable Town, MA

Median AQI 36 (Good). 94.3% of monitored days rated Good across this metro's EPA monitoring network.

36
Median AQI
94.3%
Good-air days
0
Unhealthy days
93%
Cleaner than US metros

Aggregated from EPA Air Quality System (2024), 353 monitored days. EPA AQS → · NOAA →

Insights: Barnstable Town, MA metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 36 over 353 measured days in 2024, which corresponds to a Good band and a Excellent metro-wide health grade. The monitored-day split lands at 333 Good days (94%), 19 Moderate (5%), and 1 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 46 while the highest single-day reading hit 101 (USG). Metro residents averaged roughly 28.3 clean-air days per 30-day window across the reporting year.

Across the 2020–2024 trend window, good days shifted by -6 and the median AQI moved +0 points, which classifies the multi-year trajectory as stable. The metro avoided any Unhealthy-tier days entirely, an outcome that typically reflects favorable wind patterns, lower industrial density, or effective regional emission controls. Metros with comparable AQI profiles include Bemidji, MN (84.2% good, AQI 36); Bennington, VT (91.0% good, AQI 36); Brookings, SD (79.8% good, AQI 36).

Air Quality Summary

Median AQI

36

Good

Good Days

94.3%

333 of 353 days

Max AQI

101

USG

Health Grade

Excellent

90th pct: 46

AQI Day Breakdown (2024)

Distribution of 353 monitored days across EPA AQI categories.

Good

333

94%

Moderate

19

5%

USG

1

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Excellent

The Barnstable Town, MA metro area's air quality is rated Excellent based on 94.3% good air days. No unhealthy air days were recorded in 2024.

Air quality is generally acceptable. Unusually sensitive people should monitor real-time conditions at AirNow.gov during high-pollution events.

How does the Barnstable Town, MA metro compare?

How Barnstable Town, MA compares

Good-day share better than US avg
Barnstable Town, MA 94.3%
Bemidji, MN 84.2%
US average 70.2%
Median AQI better than US avg
Barnstable Town, MA 36
Bemidji, MN 36
US average 41
Unhealthy days / yr better than US avg
Barnstable Town, MA 0
Bemidji, MN 1
US average 1

5-Year Air Quality Trend

Air quality is stable in the Barnstable Town, MA metro. Best year: 2022 (341 good days).

Year Good Moderate Unhealthy Median AQI
2020 339 10 0 36
2021 331 25 0 36
2022 341 19 0 36
2023 331 24 0 37
2024 333 19 0 36

Metros with Similar Air Quality

Metro areas across the US with a similar median AQI to Barnstable Town, MA.

Bemidji, MN

AQI 36 · 84.2% good

36

Bennington, VT

AQI 36 · 91.0% good

36

Brookings, SD

AQI 36 · 79.8% good

36

Cadillac, MI

AQI 36 · 89.1% good

36

Crestview-Fort Walton Beach-Destin, FL

AQI 36 · 93.2% good

36

Greenfield Town, MA

AQI 36 · 81.1% good

36

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Frequently Asked Questions

What is the air quality in the Barnstable Town, MA metro area? ▼
The Barnstable Town, MA metro area has a median Air Quality Index (AQI) of 36, rated "Good." 94.3% of monitored days (333 out of 353) had good air quality in 2024.
How many unhealthy air days does Barnstable Town, MA have? ▼
In 2024, the Barnstable Town, MA metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 101.
Is air quality in Barnstable Town, MA getting better or worse? ▼
Air quality in the Barnstable Town, MA metro is stable based on 5-year trends (2020-2024). Best year: 2022 with 341 good days. Worst year: 2023 with 331 good days.
What does AQI 36 mean for health? ▼
An AQI of 36 is "Good", air quality is satisfactory and poses little or no health risk. This is the best category on the EPA's AQI scale.
What is the 90th percentile AQI for Barnstable Town, MA? ▼
The 90th percentile AQI for the Barnstable Town, MA metro area is 46, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 101 (USG).
How does Barnstable Town, MA compare to other metro areas? ▼
The Barnstable Town, MA metro has 94.3% good air days. Similar metros: Bemidji, MN (84.2% good), Bennington, VT (91.0% good), Brookings, SD (79.8% good).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset, 2020–2024. The AQS collects ambient air monitoring data from state, local, and tribal monitoring agencies across the United States.

Metrics: Air Quality Index (AQI) is calculated using EPA-standard breakpoints for six criteria pollutants: PM2.5, PM10, Ozone, NO2, CO, and SO2. Median AQI, max AQI, and 90th percentile AQI are computed from daily measurements. Good days percentage reflects days with AQI 0–50.

Coverage: 501 metro areas (Core Based Statistical Areas). Only metros with active monitoring stations are included. Unmonitored areas are not represented.

Read our methodology , how this data is sourced, computed, and verified.

Source: U.S. EPA, AirNow / AQS Air Quality Index readings and pollutant concentrations · 2025