Median AQI
45
Good
Arizona · County air quality · 2025
Cochise County, Arizona
Median AQI 45 (Good). 69.9% of monitored days rated Good, direct from EPA Air Quality System stations.
- 45
- Median AQI
- 69.9%
- Good-air days
- 2
- Unhealthy days
- 32%
- Cleaner than US counties
Cochise County's 2025 annual median AQI is 45 (Good), with 69.9% Good days
According to the U.S. EPA Air Quality System, Cochise County, Arizona posted a 2025 median AQI of 45 (Good) across 365 monitored days, with 69.9% rated Good and 2 unhealthy or worse. This is an annual comparison, not today's advisory.
Data source EPA Air Quality System (AQS)
- Cleaner than US
- Cochise County's 69.9% Good-day share places it cleaner than 32% of US counties in 2025.
- Closest median-AQI peer
- Baltimore County (64.7% Good, median AQI 45) is the closest nationwide median-AQI peer to Cochise County.
- 2020–2025 trend
- Cochise County's floor-qualifying Good-day share is worsening from 2020 to 2025 (74.0% → 70.1%).
- Median AQI
- Median AQI: 45
The verdict
According to EPA Air Quality System monitoring data, Cochise County's air is good on balance, more polluted than the median US county, a median AQI of 45 with 69.9% of 365 monitored days in the Good band, driven mainly by Ozone.
- 45
- median AQI · Good
- 69.9%
- days rated Good
- Ozone
- main pollutant
- 32%
- cleaner than US counties
2 days reached Unhealthy or worse; the worst single reading hit AQI 328.
Annual release change
What changed in the 2025 EPA annual release
- Cochise County's Good-day share rose from 61.5% to 69.9% between the 2024 and 2025 EPA annual releases, a change of +8.4 percentage points.
- Cochise County's peak single-day AQI rose from 307 to 328 between the 2024 and 2025 EPA annual releases, a change of +21 points.
- Cochise County's median AQI fell from 48 to 45 between the 2024 and 2025 EPA annual releases, a change of -3 points.
Data updated August 2026
- Good · 255 d · 69.9%
- Moderate · 106 d · 29.0%
- USG · 2 d · 0.5%
- Unhealthy · 1 d · 0.3%
- Hazardous · 1 d · 0.3%
How did Cochise County's air break down in 2025?
Across 365 monitored days, 255 fell in the Good band (AQI 0–50) and 2 reached Unhealthy or worse. The worst single day peaked at AQI 328 (Hazardous).
EPA AQS →Air quality data from EPA Air Quality System (2025). 365 days monitored. Median AQI: 45 (Good).
Insights: Cochise County, Arizona. EPA monitors recorded a median Air Quality Index of 45 across 365 measured days in 2025, earning a Good classification and a Moderate health grade. Of those days, 255 (70%) fell in the Good band (AQI 0–50), 106 (29%) registered Moderate readings, and 2 (1%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 71, while the worst single-day peak hit 328 (Hazardous). Residents averaged about 21.0 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as Ozone (312 days), PM10 (50 days), PM2.5 (3 days). Across the 2020–2025 trend window, the share of monitored days rated Good shifted by -4.2 points and the median AQI moved +0 points, placing the multi-year trajectory at worsening. The annual record contains 2 days at Unhealthy or worse. On those days, the EPA recommends that sensitive groups limit prolonged outdoor exertion. Nearby counties show comparable readings: Apache (86.2% good, AQI 33); Coconino (70.1% good, AQI 46); Gila (62.7% good, AQI 47); La Paz (76.6% good, AQI 44); Maricopa (8.8% good, AQI 73); Mohave (94.8% good, AQI 17).
Air Quality Summary
Good Days
69.9%
255 of 365 monitored days
-5.1pp vs 75% target
Max AQI Recorded
328
Hazardous
Health Grade
Moderate
90th-pct AQI 71
Cochise County, Good days share 69.9%
National avg
Share of monitored days at AQI 0-50 (Good band).
Cochise County, Unhealthy-or-worse share 5.5%
National avg
Share of monitored days above AQI 150 (Unhealthy or worse). Bar maxes at 10% (worst-county ceiling).
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%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Cochise County.
- Ozone · 312 days · 85.5%
- PM10 · 50 days · 13.7%
- PM2.5 · 3 days · 0.8%
Health Impact Assessment
Moderate
Cochise County'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.
The dominant pollutant is Ozone, driving AQI on 312 of 365 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Cochise County. Highest Good-day share: 2022 (79.7%, 291 of 365 monitored days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 271 | 93 | 2 | 0 | 45 | 108 |
| 2021 | 259 | 104 | 2 | 0 | 45 | 105 |
| 2022 | 291 | 73 | 1 | 0 | 44 | 101 |
| 2023 | 272 | 90 | 3 | 0 | 44 | 108 |
| 2024 | 225 | 128 | 11 | 1 | 48 | 307 |
| 2025 | 255 | 106 | 2 | 1 | 45 | 328 |
How does Cochise County compare?
How Cochise County compares
Good-day share worse than typical
Cochise County 69.9%
Baltimore County, Maryland 64.7%
Typical US county 76.0%
Median AQI worse than typical
Cochise County 45
Baltimore County, Maryland 45
Typical US county 39
Unhealthy days / yr worse than typical
Cochise County 2
Baltimore County, Maryland 0
Typical US county 1
Counties with a similar median AQI
Nationwide peers within about the same annual median AQI as Cochise County (45), not geographic neighbors.
Baltimore County, Maryland
Median AQI 45 · 64.7% Good-day share
Bell County, Texas
Median AQI 45 · 66.0% Good-day share
Box Elder County, Utah
Median AQI 45 · 64.7% Good-day share
Bronx County, New York
Median AQI 45 · 59.2% Good-day share
Catano County, Puerto Rico
Median AQI 45 · 60.6% Good-day share
Catron County, New Mexico
Median AQI 45 · 71.7% Good-day share
Same primary pollutant: Ozone
Ozone led the AQI on the most monitored days here. These peers share that driver and the closest Good-day share (a second relationship type beyond median-AQI neighbors).
Mercer County, New Jersey
69.9% Good-day share · median AQI 43
Fremont County, Wyoming
69.6% Good-day share · median AQI 47
Coconino County, Arizona
70.1% Good-day share · median AQI 46
Sublette County, Wyoming
70.1% Good-day share · median AQI 47
Washtenaw County, Michigan
69.3% Good-day share · median AQI 41
Armstrong County, Pennsylvania
70.5% Good-day share · median AQI 41
Arizona counties on the map
Geographic containment only, other monitored counties in Arizona, independent of AQI or pollutant match.
What Cochise County's air means for you
On most days the air here is fine, but Ozone drives 2 unhealthy-or-worse days a year that sensitive groups should plan around.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-Ozone days, the guide explains what a median of 45 means for exposure. Health guidance
- See how Cochise County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Cochise County with its Arizona neighbours before drawing a conclusion about the region. All of Arizona
Based on 365 EPA-monitored days in 2025; figures reflect only days the monitors reported. Source: EPA Air Quality System annual summaries.
Keep exploring the annual AQI record
Air-quality reading list
Frequently Asked Questions
What is the air quality in Cochise County, Arizona? ▼
Cochise County has a median Air Quality Index (AQI) of 45, rated "Good." 69.9% of monitored days (255 out of 365) had good air quality in 2025.
What is the main pollutant in Cochise County? ▼
The primary pollutant in Cochise County is Ozone (O3), which was the main AQI driver on 312 days (85% of monitored days). Can trigger asthma, reduce lung function, and cause chest pain.
How many unhealthy air days does Cochise County have? ▼
In 2025, Cochise County recorded 2 unhealthy air days (1 Unhealthy, 0 Very Unhealthy, 1 Hazardous). The maximum AQI reached 328.
Is the air quality in Cochise County getting better or worse? ▼
Air quality in Cochise County is worsening 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 79.7% (291 of 365 days). Lowest qualifying Good-day share: 2024 at 61.6% (225 of 366 days).
What does AQI 45 mean for health? ▼
Cochise County's median AQI of 45 falls in the "Good" category. See the AQI category guide for what each range means for health.
How does Cochise County compare to other counties in Arizona? ▼
Cochise County has 69.9% good air days. Nearby counties in Arizona: Apache (86.2% good), Coconino (70.1% good), Gila (62.7% good), La Paz (76.6% good), Maricopa (8.8% good), Mohave (94.8% good).
What is the 90th percentile AQI in Cochise County? ▼
The 90th percentile AQI for Cochise County is 71, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 328 (Hazardous).
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025 (aqs.epa.gov). For current conditions (not shown here — this page is historical annual data), see EPA AirNow (airnow.gov). See our methodology for how AQI, median, and coverage figures are computed.
Informational only, not professional advice. Data from EPA AQS. See our disclaimer. Spotted a figure that looks wrong? Report a correction.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files for Cochise County, Arizona · 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.