Metro area air quality · 2024

Bellingham, WA

Median AQI 33 (Good). 92.8% of monitored days rated Good across this metro's EPA monitoring network.

33
Median AQI
92.8%
Good-air days
0
Unhealthy days
90%
Cleaner than US metros

Aggregated from EPA Air Quality System (2024), 361 monitored days. EPA AQS → · NOAA →

Insights: Bellingham, WA metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 33 over 361 measured days in 2024, which corresponds to a Good band and a Excellent metro-wide health grade. The monitored-day split lands at 335 Good days (93%), 26 Moderate (7%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 47 while the highest single-day reading hit 82 (Moderate). Metro residents averaged roughly 27.8 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 +9 points, which classifies the multi-year trajectory as worsening. 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 Bangor, ME (90.6% good, AQI 33); Fairmont, WV (76.6% good, AQI 33); Jackson, TN (81.0% good, AQI 33).

Air Quality Summary

Median AQI

33

Good

Good Days

92.8%

335 of 361 days

Max AQI

82

Moderate

Health Grade

Excellent

90th pct: 47

AQI Day Breakdown (2024)

Distribution of 361 monitored days across EPA AQI categories.

Good

335

93%

Moderate

26

7%

USG

0

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Excellent

The Bellingham, WA metro area's air quality is rated Excellent based on 92.8% 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 Bellingham, WA metro compare?

How Bellingham, WA compares

Good-day share better than US avg
Bellingham, WA 92.8%
Bangor, ME 90.6%
US average 70.2%
Median AQI better than US avg
Bellingham, WA 33
Bangor, ME 33
US average 41
Unhealthy days / yr better than US avg
Bellingham, WA 0
Bangor, ME 0
US average 1

5-Year Air Quality Trend

Air quality is worsening in the Bellingham, WA metro. Best year: 2020 (341 good days).

Year Good Moderate Unhealthy Median AQI
2020 341 16 4 24
2021 323 7 0 28
2022 294 40 5 32
2023 327 33 0 31
2024 335 26 0 33

Metros with Similar Air Quality

Metro areas across the US with a similar median AQI to Bellingham, WA.

Bangor, ME

AQI 33 · 90.6% good

33

Fairmont, WV

AQI 33 · 76.6% good

33

Jackson, TN

AQI 33 · 81.0% good

33

Klamath Falls, OR

AQI 33 · 70.8% good

33

Rockland, ME

AQI 33 · 96.6% good

33

Athens, TN

AQI 32 · 78.9% good

32

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Frequently Asked Questions

What is the air quality in the Bellingham, WA metro area? ▼
The Bellingham, WA metro area has a median Air Quality Index (AQI) of 33, rated "Good." 92.8% of monitored days (335 out of 361) had good air quality in 2024.
How many unhealthy air days does Bellingham, WA have? ▼
In 2024, the Bellingham, WA metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 82.
Is air quality in Bellingham, WA getting better or worse? ▼
Air quality in the Bellingham, WA metro is worsening based on 5-year trends (2020-2024). Best year: 2020 with 341 good days. Worst year: 2022 with 294 good 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.
What is the 90th percentile AQI for Bellingham, WA? ▼
The 90th percentile AQI for the Bellingham, WA metro area is 47, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 82 (Moderate).
How does Bellingham, WA compare to other metro areas? ▼
The Bellingham, WA metro has 92.8% good air days. Similar metros: Bangor, ME (90.6% good), Fairmont, WV (76.6% good), Jackson, TN (81.0% 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