La Grande, OR

EPA AQS → · NOAA →

Metro area air quality from EPA Air Quality System (2024). 366 days monitored. Median AQI: 23 (Good).

Insights: La Grande, OR metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 23 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 303 Good days (83%), 61 Moderate (17%), and 2 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 59 while the highest single-day reading hit 128 (USG). Metro residents averaged roughly 24.8 clean-air days per 30-day window across the reporting year.

Across the 2020–2024 trend window, good days shifted by +3 and the median AQI moved -4 points, which classifies the multi-year trajectory as stable. 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 Elko, NV (87.1% good, AQI 23); Ellensburg, WA (87.4% good, AQI 23); Lubbock, TX (92.2% good, AQI 23).

Air Quality Summary

Median AQI

23

Good

Good Days

82.8%

303 of 366 days

Max AQI

128

USG

Health Grade

Good

90th pct: 59

AQI Day Breakdown (2024)

Distribution of 366 monitored days across EPA AQI categories.

Good

303

83%

Moderate

61

17%

USG

2

1%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Good

The La Grande, OR metro area's air quality is rated Good based on 82.8% 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.

5-Year Air Quality Trend

Air quality is stable in the La Grande, OR metro. Best year: 2023 (305 good days).

Year Good Moderate Unhealthy Median AQI
2020 300 57 4 27
2021 304 49 2 27
2022 283 74 0 28
2023 305 56 0 26
2024 303 61 0 23

Metros with Similar Air Quality

Metro areas across the US with a similar median AQI to La Grande, OR.

Elko, NV

AQI 23 · 87.1% good

23

Ellensburg, WA

AQI 23 · 87.4% good

23

Lubbock, TX

AQI 23 · 92.2% good

23

The Dalles, OR

AQI 23 · 87.1% good

23

Twin Falls, ID

AQI 23 · 76.1% good

23

Aberdeen, SD

AQI 24 · 85.7% good

24

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PlainClimate — Climate Normals

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PlainHazard — Natural Disasters

FEMA disaster declarations. Wildfire, flood, and storm history affecting air quality. FEMA.gov →

Air Quality Guides

Learn more about air quality monitoring, pollutants, and health impacts.

Understanding AQI

What each AQI level means and who is most at risk.

Best & Worst City Air Quality

Metro area air quality rankings and what drives urban pollution.

Health Effects of Air Pollution

How PM2.5 and ozone exposure affects respiratory and cardiovascular health.

Frequently Asked Questions

What is the air quality in the La Grande, OR metro area? ▼
The La Grande, OR metro area has a median Air Quality Index (AQI) of 23, rated "Good." 82.8% of monitored days (303 out of 366) had good air quality in 2024.
How many unhealthy air days does La Grande, OR have? ▼
In 2024, the La Grande, OR metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 128.
Is air quality in La Grande, OR getting better or worse? ▼
Air quality in the La Grande, OR metro is stable based on 5-year trends (2020-2024). Best year: 2023 with 305 good days. Worst year: 2022 with 283 good days.
What does AQI 23 mean for health? ▼
An AQI of 23 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 La Grande, OR? ▼
The 90th percentile AQI for the La Grande, OR metro area is 59, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 128 (USG).
How does La Grande, OR compare to other metro areas? ▼
The La Grande, OR metro has 82.8% good air days. Similar metros: Elko, NV (87.1% good), Ellensburg, WA (87.4% good), Lubbock, TX (92.2% 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