Metro area air quality · 2025

The Dalles, OR

Median AQI 25 (Good). 86.3% of monitored days rated Good across this metro's EPA monitoring network.

25
Median AQI
86.3%
Good-air days
0
Unhealthy days
81%
Cleaner than US metros

The Dalles, OR posted a 2025 median AQI of 25 (Good) with 86.3% Good days

According to the U.S. EPA Air Quality System, the The Dalles, OR CBSA recorded a median AQI of 25 across 365 monitored days in 2025, with 86.3% 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 The Dalles, OR CBSA's 86.3% Good-day share places it cleaner than 81% of US metros in 2025.
Closest median-AQI peer
Ellensburg, WA (80.0% Good, median AQI 25) is the closest nationwide median-AQI peer to The Dalles, OR.
2020–2025 Good-day shift
The Dalles, OR's Good-day share moved -0.9 points from 2020 to 2025 (median AQI +1).
Median AQI
Median AQI: 25

Aggregated from EPA Air Quality System (2025), 365 monitored days. EPA AQS →

The verdict

The The Dalles, OR metro runs good on the EPA scale, cleaner than most US metros, a median AQI of 25 with 86.3% of 365 monitored days in the Good band.

25
median AQI · Good
86.3%
days rated Good
81%
cleaner than US metros
81
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
  • The Dalles, OR metro's peak single-day AQI fell from 93 to 81 between the 2024 and 2025 EPA annual releases, a change of -12 points.

Compared against 364 monitored days in 2024 and 365 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

Insights: The Dalles, OR metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 25 over 365 measured days in 2025, which corresponds to a Good band and a Good metro-wide health grade. The monitored-day split lands at 315 Good days (86%), 50 Moderate (14%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 54 while the highest single-day reading hit 81 (Moderate). Metro residents averaged roughly 25.9 clean-air days per 30-day window across the reporting year.

Across the 2020–2025 trend window, the share of monitored days rated Good shifted by -0.9 points and the median AQI moved +1 points, which classifies the multi-year trajectory as stable. The metro recorded no Unhealthy-tier days in this annual dataset. Metros with comparable AQI profiles include Ellensburg, WA (80.0% good, AQI 25); Mount Vernon-Anacortes, WA (97.5% good, AQI 25); Lubbock, TX (92.9% good, AQI 24).

Air Quality Summary

Median AQI

25

Good

Good Days

86.3%

315 of 365 days

Max AQI

81

Moderate

Health Grade

Good

90th pct: 54

AQI Day Breakdown (2025)

Distribution of 365 monitored days across EPA AQI categories.

Good

315

86%

Moderate

50

14%

USG

0

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Good

The The Dalles, OR metro area's air quality is rated Good based on 86.3% 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 The Dalles, OR metro compare?

How The Dalles, OR compares

Good-day share better than typical
The Dalles, OR 86.3%
Ellensburg, WA 80.0%
Typical US metro 70.6%
Median AQI better than typical
The Dalles, OR 25
Ellensburg, WA 25
Typical US metro 41
Unhealthy days / yr better than typical
The Dalles, OR 0
Ellensburg, WA 0
Typical US metro 1

5-Year Air Quality Trend

Air quality is stable in the The Dalles, OR metro. Highest Good-day share: 2022 (100.0%, 161 of 161 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 307 45 0 24
2021 287 30 1 22
2022 161 0 0 16
2023 244 40 2 27
2024 317 47 0 23
2025 315 50 0 25

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near The Dalles, OR (25).

Metros with similar unhealthy-day exposure

A second relationship type: metros whose unhealthy-or-worse day count is closest to The Dalles, OR's 0 (independent of median AQI).

More Air Quality Data

Explore EPA air quality rankings and guides across U.S. metros and counties.

Air Quality Guides

Frequently Asked Questions

What is the air quality in the The Dalles, OR metro area?
The The Dalles, OR metro area has a median Air Quality Index (AQI) of 25, rated "Good." 86.3% of monitored days (315 out of 365) had good air quality in 2025.
How many unhealthy air days does The Dalles, OR have?
In 2025, the The Dalles, OR metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 81.
Is air quality in The Dalles, OR getting better or worse?
Air quality in the The Dalles, OR 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: 2022 at 100.0% (161 of 161 days). Lowest qualifying Good-day share: 2023 at 85.3% (244 of 286 days).
What does AQI 25 mean for health?
An AQI of 25 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 The Dalles, OR?
The 90th percentile AQI for the The Dalles, OR metro area is 54, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 81 (Moderate).
How does The Dalles, OR compare to other metro areas?
The The Dalles, OR metro has 86.3% good air days. Similar metros: Ellensburg, WA (80.0% good), Mount Vernon-Anacortes, WA (97.5% good), Lubbock, TX (92.9% good).

Data Sources

Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset, 2020–2025. See our methodology for how AQI, median, and coverage figures are computed.

Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary files (metro-level) · 2020–2025

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Every figure on PlainAirData is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.