Metro area air quality · 2025
Centralia, WA
Median AQI 20 (Good). 91.3% of monitored days rated Good across this metro's EPA monitoring network.
- 20
- Median AQI
- 91.3%
- Good-air days
- 0
- Unhealthy days
- 89%
- Cleaner than US metros
Centralia, WA posted a 2025 median AQI of 20 (Good) with 91.3% Good days
According to the U.S. EPA Air Quality System, the Centralia, WA CBSA recorded a median AQI of 20 across 323 monitored days in 2025, with 91.3% 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 Centralia, WA CBSA's 91.3% Good-day share places it cleaner than 89% of US metros in 2025.
- Closest median-AQI peer
- Kahului-Wailuku-Lahaina, HI (98.1% Good, median AQI 21) is the closest nationwide median-AQI peer to Centralia, WA.
- 2020–2025 Good-day shift
- Centralia, WA's Good-day share moved -2.7 points from 2020 to 2025 (median AQI -5).
- Median AQI
- Median AQI: 20
Aggregated from EPA Air Quality System (2025), 323 monitored days. EPA AQS →
The verdict
Centralia, WA sits in the upper Good-day tercile among EPA CBSA metros on this site (91.3% of 323 monitored days). On the EPA scale the metro runs good, cleaner than most US metros, with a median AQI of 20 and 91.3% of 323 monitored days in the Good band.
- 20
- median AQI · Good
- 91.3%
- days rated Good
- 89%
- cleaner than US metros
- 74
- 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
- Centralia, WA metro's peak single-day AQI fell from 129 to 74 between the 2024 and 2025 EPA annual releases, a change of -55 points.
- Centralia, WA metro's Good-day share fell from 93.6% to 91.3% between the 2024 and 2025 EPA annual releases, a change of -2.3 percentage points.
Centralia, WA sits in the upper Good-day tercile among EPA CBSA metros on this site (91.3% of 323 monitored days). Signature read: 91.3% Good-day share (high tercile vs CBSA corpus). Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 20 over 323 measured days in 2025 (Good / Excellent). The monitored-day split lands at 295 Good (91%), 28 Moderate (9%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 48; the highest single-day reading hit 74 (Moderate).
Across 2020–2025, Good-day share shifted -2.7 points and median AQI moved -5 (stable). No Unhealthy-tier days appear in this annual dataset. Metros with comparable AQI profiles include Kahului-Wailuku-Lahaina, HI (98.1% good, AQI 21); Marquette, MI (82.4% good, AQI 19); Othello, WA (90.5% good, AQI 21).
Air Quality Summary
Median AQI
20
Good
Good Days
91.3%
295 of 323 days
Max AQI
74
Moderate
Health Grade
Excellent
90th pct: 48
AQI Day Breakdown (2025)
Distribution of 323 monitored days across EPA AQI categories.
Good
295
91%
Moderate
28
9%
USG
0
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Centralia, WA metro area's air quality is rated Excellent based on 91.3% 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 Centralia, WA metro compare?
How Centralia, WA compares
5-Year Air Quality Trend
Air quality is stable in the Centralia, WA metro. Highest Good-day share: 2020 (94.0%, 314 of 334 monitored days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 314 | 20 | 0 | 25 | 258 |
| 2021 | 328 | 22 | 0 | 23 | 71 |
| 2022 | 285 | 70 | 3 | 26 | 198 |
| 2023 | 314 | 46 | 1 | 25 | 159 |
| 2024 | 336 | 23 | 0 | 22 | 129 |
| 2025 | 295 | 28 | 0 | 20 | 74 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Centralia, WA (20).
Kahului-Wailuku-Lahaina, HI
Median AQI 21 · 98.1% Good-day share
Marquette, MI
Median AQI 19 · 82.4% Good-day share
Othello, WA
Median AQI 21 · 90.5% Good-day share
Palatka, FL
Median AQI 21 · 95.6% Good-day share
Aberdeen, WA
Median AQI 22 · 97.3% Good-day share
Bremerton-Silverdale, WA
Median AQI 22 · 95.5% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Centralia, WA's 0 (independent of median AQI).
Aberdeen, SD
0 unhealthy-or-worse days · median AQI 27
Adrian, MI
0 unhealthy-or-worse days · median AQI 41
Akron, OH
0 unhealthy-or-worse days · median AQI 45
Albany, GA
0 unhealthy-or-worse days · median AQI 46
Albany, OR
0 unhealthy-or-worse days · median AQI 27
Albany-Schenectady-Troy, NY
0 unhealthy-or-worse days · median AQI 41
Frequently Asked Questions
How many unhealthy air days does Centralia, WA have? ▼
What is the air quality in the Centralia, WA metro area? ▼
Is air quality in Centralia, WA getting better or worse? ▼
What does AQI 20 mean for health? ▼
How does Centralia, WA compare to other metro areas? ▼
What is the 90th percentile AQI for Centralia, WA? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Centralia, WA, 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, Centralia, WA · 2020–2025