Metro area air quality · 2025

Klamath Falls, OR

Median AQI 38 (Good). 64.4% of monitored days rated Good across this metro's EPA monitoring network.

38
Median AQI
64.4%
Good-air days
0
Unhealthy days
33%
Cleaner than US metros

Klamath Falls, OR posted a 2025 median AQI of 38 (Good) with 64.4% Good days

According to the U.S. EPA Air Quality System, the Klamath Falls, OR CBSA recorded a median AQI of 38 across 365 monitored days in 2025, with 64.4% 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 Klamath Falls, OR CBSA's 64.4% Good-day share places it cleaner than 33% of US metros in 2025.
Closest median-AQI peer
Appleton, WI (72.3% Good, median AQI 38) is the closest nationwide median-AQI peer to Klamath Falls, OR.
2020–2025 Good-day shift
Klamath Falls, OR's Good-day share moved +14.3 points from 2020 to 2025 (median AQI -14).
Median AQI
Median AQI: 38

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

The verdict

Klamath Falls, OR lands in the lower Good-day tercile (64.4% Good), a thinner clean-air share than most CBSA peers here. On the EPA scale the metro runs good, more polluted than the median US metro, with a median AQI of 38 and 64.4% of 365 monitored days in the Good band.

38
median AQI · Good
64.4%
days rated Good
33%
cleaner than US metros
149
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
  • Klamath Falls, OR metro's Good-day share fell from 72.8% to 64.9% between the 2024 and 2025 EPA annual releases, a change of -7.8 percentage points.
  • Klamath Falls, OR metro's Unhealthy-category days fell from 6 to 0 between the 2024 and 2025 EPA annual releases, a change of -6 days.
  • Klamath Falls, OR metro's peak single-day AQI fell from 207 to 149 between the 2024 and 2025 EPA annual releases, a change of -58 points.
  • Klamath Falls, OR metro's median AQI rose from 33 to 38 between the 2024 and 2025 EPA annual releases, a change of +5 points.

Compared against 356 monitored days in 2024 and 362 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

Klamath Falls, OR lands in the lower Good-day tercile (64.4% Good), a thinner clean-air share than most CBSA peers here. Signature read: 64.4% Good-day share (low tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 38 over 365 measured days in 2025 (Good / Moderate). The monitored-day split lands at 235 Good (64%), 127 Moderate (35%), and 3 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 69; the highest single-day reading hit 149 (USG).

Across 2020–2025, Good-day share shifted +14.3 points and median AQI moved -14 (improving). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Appleton, WI (72.3% good, AQI 38); Billings, MT (86.3% good, AQI 38); Burlington-South Burlington, VT (87.7% good, AQI 38).

Health effects of air pollution →

Air Quality Summary

Median AQI

38

Good

Good Days

64.4%

235 of 365 days

Max AQI

149

USG

Health Grade

Moderate

90th pct: 69

AQI Day Breakdown (2025)

Distribution of 365 monitored days across EPA AQI categories.

Good

235

64%

Moderate

127

35%

USG

3

1%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Moderate

The Klamath Falls, OR metro area's air quality is rated Moderate based on 64.4% 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 Klamath Falls, OR metro compare?

How Klamath Falls, OR compares

Good-day share worse than typical
Klamath Falls, OR 64.4%
Appleton, WI 72.3%
Typical US metro 70.6%
Median AQI better than typical
Klamath Falls, OR 38
Appleton, WI 38
Typical US metro 41
Unhealthy days / yr better than typical
Klamath Falls, OR 0
Appleton, WI 6
Typical US metro 1

5-Year Air Quality Trend

Air quality is improving in the Klamath Falls, OR metro. Highest Good-day share: 2024 (72.8%, 259 of 356 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 172 148 20 52
2021 162 153 25 54
2022 222 139 2 38
2023 216 137 5 39
2024 259 91 6 33
2025 235 127 0 38

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Klamath Falls, OR (38).

Appleton, WI

Median AQI 38 · 72.3% Good-day share

38

Billings, MT

Median AQI 38 · 86.3% Good-day share

38

Burlington-South Burlington, VT

Median AQI 38 · 87.7% Good-day share

38

Charlottesville, VA

Median AQI 38 · 81.0% Good-day share

38

Corning, NY

Median AQI 38 · 83.3% Good-day share

38

Dickinson, ND

Median AQI 38 · 82.7% Good-day share

38

Metros with similar unhealthy-day exposure

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

Aberdeen, SD

0 unhealthy-or-worse days · median AQI 27

27

Aberdeen, WA

0 unhealthy-or-worse days · median AQI 22

22

Adrian, MI

0 unhealthy-or-worse days · median AQI 41

41

Akron, OH

0 unhealthy-or-worse days · median AQI 45

45

Albany, GA

0 unhealthy-or-worse days · median AQI 46

46

Albany, OR

0 unhealthy-or-worse days · median AQI 27

27

Frequently Asked Questions

How many unhealthy air days does Klamath Falls, OR have? ▼
In 2025, the Klamath Falls, OR metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 149.
What is the air quality in the Klamath Falls, OR metro area? ▼
The Klamath Falls, OR metro area has a median Air Quality Index (AQI) of 38, rated "Good." 64.4% of monitored days (235 out of 365) had good air quality in 2025.
Is air quality in Klamath Falls, OR getting better or worse? ▼
Air quality in the Klamath Falls, OR metro is improving across floor-qualifying years (2020-2025); years with fewer than 100 monitored days are excluded from that direction. Highest qualifying Good-day share: 2024 at 72.8% (259 of 356 days). Lowest qualifying Good-day share: 2021 at 47.6% (162 of 340 days).
What does AQI 38 mean for health? ▼
An AQI of 38 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 Klamath Falls, OR compare to other metro areas? ▼
The Klamath Falls, OR metro has 64.4% good air days. Similar metros: Appleton, WI (72.3% good), Billings, MT (86.3% good), Burlington-South Burlington, VT (87.7% good).
What is the 90th percentile AQI for Klamath Falls, OR? ▼
The 90th percentile AQI for the Klamath Falls, OR metro area is 69, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 149 (USG).

Data Sources

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