Metro area air quality · 2025

Barnstable Town, MA

Median AQI 36 (Good). 93.7% of monitored days rated Good across this metro's EPA monitoring network.

Compiled by PlainAirData · August 23, 2026

36
Median AQI: 93.7%
Good-air days: 0
Unhealthy days: 92%
Cleaner than US metros

Barnstable Town, MA posted a 2025 median AQI of 36 (Good) with 93.7% Good days

According to the U.S. EPA Air Quality System, the Barnstable Town, MA CBSA recorded a median AQI of 36 across 364 monitored days in 2025, with 93.7% rated Good and 0 unhealthy or worse. This is an annual metro comparison, not a live advisory.

Data source EPA Air Quality System (AQS)

Cleaner than US metros: The Barnstable Town, MA CBSA's 93.7% Good-day share places it cleaner than 92% of US metros in 2025.
Closest median-AQI peer: Atlantic City-Hammonton, NJ (82.2% Good, median AQI 36) is the closest nationwide median-AQI peer to Barnstable Town, MA.
2020–2025 Good-day shift: Barnstable Town, MA's Good-day share moved -2.7 points from 2020 to 2025 (median AQI +0).
Median AQI: Median AQI: 36

Aggregated from EPA Air Quality System (2025), 364 monitored days. EPA AQS →

The verdict

The Barnstable Town, MA metro runs good on the EPA scale, among the cleanest 10% of US metros, a median AQI of 36 with 93.7% of 364 monitored days in the Good band.

36
median AQI · Good: 93.7%
days rated Good: 92%
cleaner than US metros: 129
worst single reading

No day crossed into the Unhealthy tier across the metro's monitors in 2025.

Barnstable Town, MA metro's peak single-day AQI rose from 101 to 129 between the 2024 and 2025 EPA annual releases, a change of +28 points.

Insights: Barnstable Town, MA metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 36 over 364 measured days in 2025, which corresponds to a Good band and a Excellent metro-wide health grade. The monitored-day split lands at 341 Good days (94%), 20 Moderate (5%), and 3 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 46 while the highest single-day reading hit 129 (USG). Metro residents averaged roughly 28.1 clean-air days per 30-day window across the reporting year.

Across the 2020–2025 trend window, the share of monitored days rated Good shifted by -2.7 points and the median AQI moved +0 points, which classifies the multi-year trajectory as stable. The metro recorded no Unhealthy-tier days in this annual dataset. Metros with comparable AQI profiles include Atlantic City-Hammonton, NJ (82.2% good, AQI 36); Bemidji, MN (79.1% good, AQI 36); Claremont-Lebanon, NH-VT (83.6% good, AQI 36).

Air Quality Summary

Median AQI

Good

Good Days

93.7%

341 of 364 days

Max AQI

129

USG

Health Grade

Excellent

90th pct: 46

AQI Day Breakdown (2025)

Distribution of 364 monitored days across EPA AQI categories.

Good

341

94%

Moderate

USG

Unhealthy

Very Unhealthy

Hazardous

Health Impact Assessment

Excellent

The Barnstable Town, MA metro area's air quality is rated Excellent based on 93.7% good air days. No unhealthy air days were recorded in 2025.

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

Compare against

Good-day share better than typical

Barnstable Town, MA 93.7%

Atlantic City-Hammonton, NJ 82.2%

Typical US metro 70.6%

Median AQI better than typical

Barnstable Town, MA 36

Atlantic City-Hammonton, NJ 36

Typical US metro 41

Unhealthy days / yr better than typical

Barnstable Town, MA 0

Atlantic City-Hammonton, NJ 0

Typical US metro 1

5-Year Air Quality Trend

Air quality is stable in the Barnstable Town, MA metro. Highest Good-day share: 2020 (97.1%, 339 of 349 monitored days).

Year	Good	Moderate	Median AQI	Max AQI
2020	339	10	36	108
2021	331	25	36	126
2022	341	19	36	93
2023	331	24	37	140
2024	333	19	36	101
2025	341	20	36	129

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Barnstable Town, MA (36).

Atlantic City-Hammonton, NJ

Median AQI 36 · 82.2% Good-day share

Bemidji, MN

Median AQI 36 · 79.1% Good-day share

Claremont-Lebanon, NH-VT

Median AQI 36 · 83.6% Good-day share

Crestview-Fort Walton Beach-Destin, FL

Median AQI 36 · 93.9% Good-day share

East Stroudsburg, PA

Median AQI 36 · 88.3% Good-day share

Jackson, TN

Median AQI 36 · 74.3% Good-day share

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to Barnstable Town, MA's 0 (independent of median AQI).

Aberdeen, SD

0 unhealthy-or-worse days · median AQI 27

Aberdeen, WA

0 unhealthy-or-worse days · median AQI 22

Adrian, MI

0 unhealthy-or-worse days · median AQI 41

Akron, OH

0 unhealthy-or-worse days · median AQI 45

Albany, GA

0 unhealthy-or-worse days · median AQI 46

Albany, OR

0 unhealthy-or-worse days · median AQI 27

More Air Quality Data

Explore EPA air quality rankings and guides across U.S. metros and counties.

Cleanest Metro Areas

U.S. metros ranked by their share of Good air-quality days.

Worst Air Quality

Counties and metros with the most unhealthy air days.

All Metro Areas

Annual AQI by CBSA for every monitored U.S. metro area.

Best and Worst City Air

What drives urban air quality and how metro areas compare.

Air Quality Guides

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." 93.7% of monitored days (341 out of 364) had good air quality in 2025.

How many unhealthy air days does Barnstable Town, MA have? ▼

In 2025, the Barnstable Town, MA metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 129.

Is air quality in Barnstable Town, MA getting better or worse? ▼

Air quality in the Barnstable Town, MA metro is stable across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2020 at 97.1% (339 of 349 days). Lowest qualifying Good-day share: 2021 at 93.0% (331 of 356 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 129 (USG).

How does Barnstable Town, MA compare to other metro areas? ▼

The Barnstable Town, MA metro has 93.7% good air days. Similar metros: Atlantic City-Hammonton, NJ (82.2% good), Bemidji, MN (79.1% good), Claremont-Lebanon, NH-VT (83.6% good).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset, 2020–2025. See our methodology for how AQI, median, and coverage figures are computed.

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

Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary files (metro-level) · 2020–2025 Accessed 2026-07-06

Send the source-year summary or download its ready-to-use data card.

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Every figure on PlainAirData is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.