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.

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

Barnstable Town, MA sits in the upper Good-day tercile among EPA CBSA metros on this site (93.7% of 364 monitored days). On the EPA scale the metro runs good, among the cleanest 10% of US metros, with a median AQI of 36 and 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.

Annual release change

What changed in the 2025 EPA annual release

2024 → 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.

Compared against 352 monitored days in 2024 and 361 in 2025. These are arithmetic differences between two stored EPA annual summaries, not a cause claim or a live advisory.

National release changes Two-year CSV

Barnstable Town, MA sits in the upper Good-day tercile among EPA CBSA metros on this site (93.7% of 364 monitored days). Signature read: 93.7% Good-day share (high tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 36 over 364 measured days in 2025 (Good / Excellent). The monitored-day split lands at 341 Good (94%), 20 Moderate (5%), and 3 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 46; the highest single-day reading hit 129 (USG).

Across 2020–2025, Good-day share shifted -2.7 points and median AQI moved +0 (stable). No Unhealthy-tier days appear 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).

Best and worst city air quality →

Air Quality Summary

Median AQI

36

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

20

5%

USG

3

1%

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 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

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 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
2025 341 20 0 36

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

36

Bemidji, MN

Median AQI 36 · 79.1% Good-day share

36

Claremont-Lebanon, NH-VT

Median AQI 36 · 83.6% Good-day share

36

Crestview-Fort Walton Beach-Destin, FL

Median AQI 36 · 93.9% Good-day share

36

East Stroudsburg, PA

Median AQI 36 · 88.3% Good-day share

36

Jackson, TN

Median AQI 36 · 74.3% Good-day share

36

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

27

Aberdeen, WA

0 unhealthy-or-worse days · median AQI 22

22

Adrian, MI

0 unhealthy-or-worse days · median AQI 41

41

Akron, OH

0 unhealthy-or-worse days · median AQI 45

45

Albany, GA

0 unhealthy-or-worse days · median AQI 46

46

Albany, OR

0 unhealthy-or-worse days · median AQI 27

27

Frequently Asked Questions

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.
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.
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.
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).
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).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Barnstable Town, MA, 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, Barnstable Town, MA · 2020–2025