Metro area air quality · 2025

Bangor, ME

Median AQI 33 (Good). 84.2% of monitored days rated Good across this metro's EPA monitoring network.

33
Median AQI
84.2%
Good-air days
1
Unhealthy days
76%
Cleaner than US metros

Bangor, ME posted a 2025 median AQI of 33 (Good) with 84.2% Good days

According to the U.S. EPA Air Quality System, the Bangor, ME CBSA recorded a median AQI of 33 across 355 monitored days in 2025, with 84.2% rated Good and 1 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 Bangor, ME CBSA's 84.2% Good-day share places it cleaner than 76% of US metros in 2025.
Closest median-AQI peer
Clarksburg, WV (72.4% Good, median AQI 33) is the closest nationwide median-AQI peer to Bangor, ME.
2020–2025 Good-day shift
Bangor, ME's Good-day share moved -7.7 points from 2020 to 2025 (median AQI +0).
Median AQI
Median AQI: 33

Aggregated from EPA Air Quality System (2025), 355 monitored days. EPA AQS →

The verdict

Bangor, ME sits in the upper Good-day tercile among EPA CBSA metros on this site (84.2% of 355 monitored days). On the EPA scale the metro runs good, cleaner than most US metros, with a median AQI of 33 and 84.2% of 355 monitored days in the Good band.

33
median AQI · Good
84.2%
days rated Good
76%
cleaner than US metros
170
worst single reading

1 day reached Unhealthy or worse across the metro's monitors in 2025.

Annual release change

What changed in the 2025 EPA annual release

2024 → 2025
  • Bangor, ME metro's peak single-day AQI rose from 84 to 170 between the 2024 and 2025 EPA annual releases, a change of +86 points.
  • Bangor, ME metro's Good-day share fell from 90.6% to 85.4% between the 2024 and 2025 EPA annual releases, a change of -5.2 percentage points.
  • Bangor, ME metro's Unhealthy-category days rose from 0 to 1 between the 2024 and 2025 EPA annual releases, a change of +1 days.

Compared against 362 monitored days in 2024 and 350 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

Bangor, ME sits in the upper Good-day tercile among EPA CBSA metros on this site (84.2% of 355 monitored days). Signature read: 84.2% 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 33 over 355 measured days in 2025 (Good / Good). The monitored-day split lands at 299 Good (84%), 50 Moderate (14%), and 5 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 58; the highest single-day reading hit 170 (Unhealthy).

Across 2020–2025, Good-day share shifted -7.7 points and median AQI moved +0 (worsening). The annual record contains 1 day at Unhealthy or worse. Metros with comparable AQI profiles include Clarksburg, WV (72.4% good, AQI 33); Grants Pass, OR (68.2% good, AQI 33); Lawrenceburg, TN (81.5% good, AQI 33).

Health effects of air pollution →

Air Quality Summary

Median AQI

33

Good

Good Days

84.2%

299 of 355 days

Max AQI

170

Unhealthy

Health Grade

Good

90th pct: 58

AQI Day Breakdown (2025)

Distribution of 355 monitored days across EPA AQI categories.

Good

299

84%

Moderate

50

14%

USG

5

1%

Unhealthy

1

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Good

The Bangor, ME metro area's air quality is rated Good based on 84.2% good air days. There were 1 unhealthy days in 2025 when outdoor activity should be limited.

Air quality is acceptable most days, but 5 days reached "Unhealthy for Sensitive Groups" and peak AQI reached 170. Sensitive groups should monitor real-time conditions at AirNow.gov.

How does the Bangor, ME metro compare?

How Bangor, ME compares

Good-day share better than typical
Bangor, ME 84.2%
Clarksburg, WV 72.4%
Typical US metro 70.6%
Median AQI better than typical
Bangor, ME 33
Clarksburg, WV 33
Typical US metro 41
Unhealthy days / yr about typical
Bangor, ME 1
Clarksburg, WV 0
Typical US metro 1

5-Year Air Quality Trend

Air quality is worsening in the Bangor, ME metro. Highest Good-day share: 2020 (93.1%, 338 of 363 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 338 25 0 33
2021 326 36 0 33
2022 324 37 0 33
2023 294 64 0 35
2024 328 34 0 33
2025 299 50 1 33

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Bangor, ME (33).

Clarksburg, WV

Median AQI 33 · 72.4% Good-day share

33

Grants Pass, OR

Median AQI 33 · 68.2% Good-day share

33

Lawrenceburg, TN

Median AQI 33 · 81.5% Good-day share

33

Roanoke Rapids, NC

Median AQI 33 · 78.1% Good-day share

33

Rockland, ME

Median AQI 33 · 97.8% Good-day share

33

Vallejo-Fairfield, CA

Median AQI 33 · 99.2% Good-day share

33

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to Bangor, ME's 1 (independent of median AQI).

Ann Arbor, MI

1 unhealthy-or-worse days · median AQI 41

41

Baraboo, WI

1 unhealthy-or-worse days · median AQI 35

35

Bartlesville, OK

1 unhealthy-or-worse days · median AQI 44

44

Beaumont-Port Arthur, TX

1 unhealthy-or-worse days · median AQI 52

52

Beaver Dam, WI

1 unhealthy-or-worse days · median AQI 40

40

Bellingham, WA

1 unhealthy-or-worse days · median AQI 31

31

Frequently Asked Questions

How many unhealthy air days does Bangor, ME have? ▼
In 2025, the Bangor, ME metro area recorded 1 unhealthy air days (1 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 170.
What is the air quality in the Bangor, ME metro area? ▼
The Bangor, ME metro area has a median Air Quality Index (AQI) of 33, rated "Good." 84.2% of monitored days (299 out of 355) had good air quality in 2025.
Is air quality in Bangor, ME getting better or worse? ▼
Air quality in the Bangor, ME metro is worsening 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 93.1% (338 of 363 days). Lowest qualifying Good-day share: 2023 at 82.1% (294 of 358 days).
What does AQI 33 mean for health? ▼
An AQI of 33 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 Bangor, ME compare to other metro areas? ▼
The Bangor, ME metro has 84.2% good air days. Similar metros: Clarksburg, WV (72.4% good), Grants Pass, OR (68.2% good), Lawrenceburg, TN (81.5% good).
What is the 90th percentile AQI for Bangor, ME? ▼
The 90th percentile AQI for the Bangor, ME metro area is 58, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 170 (Unhealthy).

Data Sources

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