Metro area air quality · 2025

Red Bluff, CA

Median AQI 38 (Good). 77.8% of monitored days rated Good across this metro's EPA monitoring network.

38
Median AQI
77.8%
Good-air days
0
Unhealthy days
62%
Cleaner than US metros

Red Bluff, CA posted a 2025 median AQI of 38 (Good) with 77.8% Good days

According to the U.S. EPA Air Quality System, the Red Bluff, CA CBSA recorded a median AQI of 38 across 365 monitored days in 2025, with 77.8% 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 Red Bluff, CA CBSA's 77.8% Good-day share places it cleaner than 62% 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 Red Bluff, CA.
2020–2025 Good-day shift
Red Bluff, CA's Good-day share moved +16.7 points from 2020 to 2025 (median AQI -8).
Median AQI
Median AQI: 38

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

The verdict

Red Bluff, CA's Good-day share (77.8%) sits in the middle CBSA tercile on this extract. On the EPA scale the metro runs good, cleaner than the median US metro, with a median AQI of 38 and 77.8% of 365 monitored days in the Good band.

38
median AQI · Good
77.8%
days rated Good
62%
cleaner than US metros
108
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
  • Red Bluff, CA metro's Good-day share rose from 69.2% to 78.0% between the 2024 and 2025 EPA annual releases, a change of +8.8 percentage points.
  • Red Bluff, CA metro's median AQI fell from 43 to 38 between the 2024 and 2025 EPA annual releases, a change of -5 points.

Compared against 364 monitored days in 2024 and 364 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

Red Bluff, CA's Good-day share (77.8%) sits in the middle CBSA tercile on this extract. Signature read: 77.8% Good-day share (mid 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 / Good). The monitored-day split lands at 284 Good (78%), 80 Moderate (22%), and 1 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 54; the highest single-day reading hit 108 (USG).

Across 2020–2025, Good-day share shifted +16.7 points and median AQI moved -8 (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).

Understanding AQI →

Air Quality Summary

Median AQI

38

Good

Good Days

77.8%

284 of 365 days

Max AQI

108

USG

Health Grade

Good

90th pct: 54

AQI Day Breakdown (2025)

Distribution of 365 monitored days across EPA AQI categories.

Good

284

78%

Moderate

80

22%

USG

1

0%

Unhealthy

0

0%

Very Unhealthy

0

0%

Hazardous

0

0%

Health Impact Assessment

Good

The Red Bluff, CA metro area's air quality is rated Good based on 77.8% 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 Red Bluff, CA metro compare?

How Red Bluff, CA compares

Good-day share better than typical
Red Bluff, CA 77.8%
Appleton, WI 72.3%
Typical US metro 70.6%
Median AQI better than typical
Red Bluff, CA 38
Appleton, WI 38
Typical US metro 41
Unhealthy days / yr better than typical
Red Bluff, CA 0
Appleton, WI 6
Typical US metro 1

5-Year Air Quality Trend

Air quality is improving in the Red Bluff, CA metro. Highest Good-day share: 2025 (78.0%, 284 of 364 monitored days).

Year Good Moderate Unhealthy Median AQI
2020 216 117 19 46
2021 207 122 15 47
2022 245 117 0 44
2023 242 117 0 44
2024 252 112 0 43
2025 284 80 0 38

Metros with a similar median AQI

CBSA peers nationwide whose annual median AQI sits near Red Bluff, CA (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 Red Bluff, CA'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 Red Bluff, CA have? ▼
In 2025, the Red Bluff, CA metro area recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 108.
What is the air quality in the Red Bluff, CA metro area? ▼
The Red Bluff, CA metro area has a median Air Quality Index (AQI) of 38, rated "Good." 77.8% of monitored days (284 out of 365) had good air quality in 2025.
Is air quality in Red Bluff, CA getting better or worse? ▼
Air quality in the Red Bluff, CA 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: 2025 at 78.0% (284 of 364 days). Lowest qualifying Good-day share: 2021 at 60.2% (207 of 344 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 Red Bluff, CA compare to other metro areas? ▼
The Red Bluff, CA metro has 77.8% 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 Red Bluff, CA? ▼
The 90th percentile AQI for the Red Bluff, CA metro area is 54, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 108 (USG).

Data Sources

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