Metro area air quality · 2024

Pullman, WA

Median AQI 20 (Good). 84.7% of monitored days rated Good across this metro's EPA monitoring network.

20
Median AQI
84.7%
Good-air days
0
Unhealthy days
75%
Cleaner than US metros

Aggregated from EPA Air Quality System (2024), 366 monitored days. EPA AQS → · NOAA →

Insights: Pullman, WA metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 20 over 366 measured days in 2024, which corresponds to a Good band and a Good metro-wide health grade. The monitored-day split lands at 310 Good days (85%), 56 Moderate (15%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 54 while the highest single-day reading hit 97 (Moderate). Metro residents averaged roughly 25.4 clean-air days per 30-day window across the reporting year.

Across the 2020–2024 trend window, good days shifted by -25 and the median AQI moved +1 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 Aberdeen, WA (96.5% good, AQI 20); Winona, MN (93.4% good, AQI 20); Bremerton-Silverdale, WA (97.2% good, AQI 19).

Air Quality Summary

Median AQI

20

Good

Good Days

84.7%

310 of 366 days

Max AQI

97

Moderate

Health Grade

Good

90th pct: 54

AQI Day Breakdown (2024)

Distribution of 366 monitored days across EPA AQI categories.

Good

310

85%

Moderate

56

15%

USG

0

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Good

The Pullman, WA metro area's air quality is rated Good based on 84.7% 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 Pullman, WA metro compare?

How Pullman, WA compares

Good-day share better than US avg
Pullman, WA 84.7%
Aberdeen, WA 96.5%
US average 70.2%
Median AQI better than US avg
Pullman, WA 20
Aberdeen, WA 20
US average 41
Unhealthy days / yr better than US avg
Pullman, WA 0
Aberdeen, WA 0
US average 1

5-Year Air Quality Trend

Air quality is worsening in the Pullman, WA metro. Best year: 2020 (335 good days).

Year Good Moderate Unhealthy Median AQI
2020 335 23 5 19
2021 310 45 4 22
2022 306 55 4 24
2023 323 40 0 26
2024 310 56 0 20

Metros with Similar Air Quality

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

Aberdeen, WA

AQI 20 · 96.5% good

20

Winona, MN

AQI 20 · 93.4% good

20

Bremerton-Silverdale, WA

AQI 19 · 97.2% good

19

Hailey, ID

AQI 19 · 86.3% good

19

Hilo, HI

AQI 21 · 97.0% good

21

Kahului-Wailuku-Lahaina, HI

AQI 21 · 99.7% good

21

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Air Quality Guides

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Health Effects of Air Pollution

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Frequently Asked Questions

What is the air quality in the Pullman, WA metro area? ▼
The Pullman, WA metro area has a median Air Quality Index (AQI) of 20, rated "Good." 84.7% of monitored days (310 out of 366) had good air quality in 2024.
How many unhealthy air days does Pullman, WA have? ▼
In 2024, the Pullman, WA metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 97.
Is air quality in Pullman, WA getting better or worse? ▼
Air quality in the Pullman, WA metro is worsening based on 5-year trends (2020-2024). Best year: 2020 with 335 good days. Worst year: 2022 with 306 good days.
What does AQI 20 mean for health? ▼
An AQI of 20 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 Pullman, WA? ▼
The 90th percentile AQI for the Pullman, WA metro area is 54, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 97 (Moderate).
How does Pullman, WA compare to other metro areas? ▼
The Pullman, WA metro has 84.7% good air days. Similar metros: Aberdeen, WA (96.5% good), Winona, MN (93.4% good), Bremerton-Silverdale, WA (97.2% 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