Metro area air quality · 2025
Sierra Vista-Douglas, AZ
Median AQI 45 (Good). 69.9% of monitored days rated Good across this metro's EPA monitoring network.
- 45
- Median AQI
- 69.9%
- Good-air days
- 2
- Unhealthy days
- 45%
- Cleaner than US metros
Sierra Vista-Douglas, AZ posted a 2025 median AQI of 45 (Good) with 69.9% Good days
According to the U.S. EPA Air Quality System, the Sierra Vista-Douglas, AZ CBSA recorded a median AQI of 45 across 365 monitored days in 2025, with 69.9% rated Good and 2 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 Sierra Vista-Douglas, AZ CBSA's 69.9% Good-day share places it cleaner than 45% of US metros in 2025.
- Closest median-AQI peer
- Akron, OH (61.6% Good, median AQI 45) is the closest nationwide median-AQI peer to Sierra Vista-Douglas, AZ.
- 2020–2025 Good-day shift
- Sierra Vista-Douglas, AZ's Good-day share moved -4.0 points from 2020 to 2025 (median AQI +0).
- Median AQI
- Median AQI: 45
Aggregated from EPA Air Quality System (2025), 365 monitored days. EPA AQS →
The verdict
The Sierra Vista-Douglas, AZ metro runs good on the EPA scale, more polluted than the median US metro, a median AQI of 45 with 69.9% of 365 monitored days in the Good band.
- 45
- median AQI · Good
- 69.9%
- days rated Good
- 45%
- cleaner than US metros
- 328
- worst single reading
2 days reached Unhealthy or worse across the metro's monitors in 2025.
Annual release change
What changed in the 2025 EPA annual release
- Sierra Vista-Douglas, AZ metro's Good-day share rose from 63.6% to 70.4% between the 2024 and 2025 EPA annual releases, a change of +6.9 percentage points.
- Sierra Vista-Douglas, AZ metro's peak single-day AQI rose from 307 to 328 between the 2024 and 2025 EPA annual releases, a change of +21 points.
- Sierra Vista-Douglas, AZ metro's median AQI fell from 48 to 45 between the 2024 and 2025 EPA annual releases, a change of -3 points.
Insights: Sierra Vista-Douglas, AZ metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 45 over 365 measured days in 2025, which corresponds to a Good band and a Moderate metro-wide health grade. The monitored-day split lands at 255 Good days (70%), 106 Moderate (29%), and 2 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 71 while the highest single-day reading hit 328 (Hazardous). Metro residents averaged roughly 21.0 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 -4.0 points and the median AQI moved +0 points, which classifies the multi-year trajectory as worsening. The annual record contains 2 days at Unhealthy or worse. On those days, the EPA recommends that sensitive groups limit prolonged outdoor exertion. Metros with comparable AQI profiles include Akron, OH (61.6% good, AQI 45); Ardmore, OK (67.9% good, AQI 45); Asheville, NC (69.9% good, AQI 45).
Air Quality Summary
Median AQI
45
Good
Good Days
69.9%
255 of 365 days
Max AQI
328
Hazardous
Health Grade
Moderate
90th pct: 71
AQI Day Breakdown (2025)
Distribution of 365 monitored days across EPA AQI categories.
Good
255
70%
Moderate
106
29%
USG
2
1%
Unhealthy
1
0%
Very Unhealthy
0
0%
Hazardous
1
0%
Health Impact Assessment
The Sierra Vista-Douglas, AZ metro area's air quality is rated Moderate based on 69.9% good air days. There were 2 unhealthy days in 2025 when outdoor activity should be limited.
Air quality posed significant health risk in 2025. Sensitive groups, including people with asthma, COPD, cardiovascular conditions, children, pregnant women, and adults over 65, should monitor AirNow.gov alerts and limit outdoor activity on Unhealthy (AQI 151+) and Very Unhealthy (201+) days. Peak readings reached AQI 328, well into the Hazardous range.
Sensitive group advisory
People with asthma, COPD, heart disease, children, pregnant women, and adults 65+ should follow EPA AQI alerts daily and limit outdoor exertion when AQI exceeds 100. Real-time conditions: airnow.gov.
How does the Sierra Vista-Douglas, AZ metro compare?
How Sierra Vista-Douglas, AZ compares
5-Year Air Quality Trend
Air quality is worsening in the Sierra Vista-Douglas, AZ metro. Highest Good-day share: 2022 (79.9%, 291 of 364 monitored days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 271 | 93 | 0 | 45 | 108 |
| 2021 | 259 | 104 | 0 | 45 | 105 |
| 2022 | 291 | 73 | 0 | 44 | 101 |
| 2023 | 272 | 90 | 0 | 44 | 108 |
| 2024 | 225 | 128 | 1 | 48 | 307 |
| 2025 | 255 | 106 | 1 | 45 | 328 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Sierra Vista-Douglas, AZ (45).
Akron, OH
Median AQI 45 · 61.6% Good-day share
Ardmore, OK
Median AQI 45 · 67.9% Good-day share
Asheville, NC
Median AQI 45 · 69.9% Good-day share
Cheyenne, WY
Median AQI 45 · 75.1% Good-day share
Clinton, IA
Median AQI 45 · 59.5% Good-day share
Fort Dodge, IA
Median AQI 45 · 59.2% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Sierra Vista-Douglas, AZ's 2 (independent of median AQI).
Bridgeport-Stamford-Norwalk, CT
2 unhealthy-or-worse days · median AQI 44
Chattanooga, TN-GA
2 unhealthy-or-worse days · median AQI 49
Cincinnati, OH-KY-IN
2 unhealthy-or-worse days · median AQI 56
Columbus, GA-AL
2 unhealthy-or-worse days · median AQI 48
Davenport-Moline-Rock Island, IA-IL
2 unhealthy-or-worse days · median AQI 46
Grand Rapids-Wyoming, MI
2 unhealthy-or-worse days · median AQI 52
More Air Quality Data
Explore EPA air quality rankings and guides across U.S. metros and counties.
Cleanest Metro Areas
U.S. metros ranked by their share of Good air-quality days.
Worst Air Quality
Counties and metros with the most unhealthy air days.
All Metro Areas
Annual AQI by CBSA for every monitored U.S. metro area.
Best and Worst City Air
What drives urban air quality and how metro areas compare.
Air Quality Guides
Frequently Asked Questions
What is the air quality in the Sierra Vista-Douglas, AZ metro area? ▼
How many unhealthy air days does Sierra Vista-Douglas, AZ have? ▼
Is air quality in Sierra Vista-Douglas, AZ getting better or worse? ▼
What does AQI 45 mean for health? ▼
What is the 90th percentile AQI for Sierra Vista-Douglas, AZ? ▼
How does Sierra Vista-Douglas, AZ compare to other metro areas? ▼
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.
Read our methodology , how this data is sourced, computed, and verified.
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.