Metro area air quality · 2025
Nogales, AZ
Median AQI 49 (Good). 52.2% of monitored days rated Good across this metro's EPA monitoring network.
- 49
- Median AQI
- 52.2%
- Good-air days
- 1
- Unhealthy days
- 15%
- Cleaner than US metros
Nogales, AZ posted a 2025 median AQI of 49 (Good) with 52.2% Good days
According to the U.S. EPA Air Quality System, the Nogales, AZ CBSA recorded a median AQI of 49 across 364 monitored days in 2025, with 52.2% rated Good and 1 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 Nogales, AZ CBSA's 52.2% Good-day share places it cleaner than 15% of US metros in 2025.
- Closest median-AQI peer
- Canton-Massillon, OH (53.1% Good, median AQI 49) is the closest nationwide median-AQI peer to Nogales, AZ.
- 2020–2025 Good-day shift
- Nogales, AZ's Good-day share moved -5.9 points from 2020 to 2025 (median AQI +5).
- Median AQI
- Median AQI: 49
Aggregated from EPA Air Quality System (2025), 364 monitored days. EPA AQS →
The verdict
Nogales, AZ lands in the lower Good-day tercile (52.2% Good), a thinner clean-air share than most CBSA peers here. On the EPA scale the metro runs good, among the more polluted US metros, with a median AQI of 49 and 52.2% of 364 monitored days in the Good band.
- 49
- median AQI · Good
- 52.2%
- days rated Good
- 15%
- cleaner than US metros
- 187
- worst single reading
1 day reached Unhealthy or worse across the metro's monitors in 2025.
Annual release change
What changed in the 2025 EPA annual release
- Nogales, AZ metro's peak single-day AQI fell from 494 to 187 between the 2024 and 2025 EPA annual releases, a change of -307 points.
- Nogales, AZ metro's Good-day share fell from 60.5% to 52.5% between the 2024 and 2025 EPA annual releases, a change of -8.0 percentage points.
- Nogales, AZ metro's median AQI rose from 43 to 49 between the 2024 and 2025 EPA annual releases, a change of +6 points.
- Nogales, AZ metro's Unhealthy-category days rose from 0 to 1 between the 2024 and 2025 EPA annual releases, a change of +1 days.
Nogales, AZ lands in the lower Good-day tercile (52.2% Good), a thinner clean-air share than most CBSA peers here. Signature read: 52.2% 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 49 over 364 measured days in 2025 (Good / Moderate). The monitored-day split lands at 190 Good (52%), 171 Moderate (47%), and 2 Unhealthy-for-Sensitive-Groups (1%). The 90th-percentile AQI finished at 73; the highest single-day reading hit 187 (Unhealthy).
Across 2020–2025, Good-day share shifted -5.9 points and median AQI moved +5 (worsening). The annual record contains 1 day at Unhealthy or worse. Metros with comparable AQI profiles include Canton-Massillon, OH (53.1% good, AQI 49); Carlsbad-Artesia, NM (53.7% good, AQI 49); Chattanooga, TN-GA (51.0% good, AQI 49).
Air Quality Summary
Median AQI
49
Good
Good Days
52.2%
190 of 364 days
Max AQI
187
Unhealthy
Health Grade
Moderate
90th pct: 73
AQI Day Breakdown (2025)
Distribution of 364 monitored days across EPA AQI categories.
Good
190
52%
Moderate
171
47%
USG
2
1%
Unhealthy
1
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Nogales, AZ metro area's air quality is rated Moderate based on 52.2% good air days. There were 1 unhealthy days in 2025 when outdoor activity should be limited.
Air quality is acceptable most days, but 2 days reached "Unhealthy for Sensitive Groups" and peak AQI reached 187. Sensitive groups should monitor real-time conditions at AirNow.gov.
How does the Nogales, AZ metro compare?
How Nogales, AZ compares
5-Year Air Quality Trend
Air quality is worsening in the Nogales, AZ metro. Highest Good-day share: 2023 (74.2%, 265 of 357 monitored days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 208 | 147 | 1 | 44 | 170 |
| 2021 | 169 | 189 | 1 | 52 | 171 |
| 2022 | 220 | 136 | 0 | 43 | 138 |
| 2023 | 265 | 92 | 0 | 37 | 145 |
| 2024 | 213 | 139 | 0 | 43 | 494 |
| 2025 | 190 | 171 | 1 | 49 | 187 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Nogales, AZ (49).
Canton-Massillon, OH
Median AQI 49 · 53.1% Good-day share
Carlsbad-Artesia, NM
Median AQI 49 · 53.7% Good-day share
Chattanooga, TN-GA
Median AQI 49 · 51.0% Good-day share
Kingsville, TX
Median AQI 49 · 51.7% Good-day share
Laramie, WY
Median AQI 49 · 55.6% Good-day share
Miami, OK
Median AQI 49 · 53.7% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Nogales, AZ's 1 (independent of median AQI).
Ann Arbor, MI
1 unhealthy-or-worse days · median AQI 41
Bangor, ME
1 unhealthy-or-worse days · median AQI 33
Baraboo, WI
1 unhealthy-or-worse days · median AQI 35
Bartlesville, OK
1 unhealthy-or-worse days · median AQI 44
Beaumont-Port Arthur, TX
1 unhealthy-or-worse days · median AQI 52
Beaver Dam, WI
1 unhealthy-or-worse days · median AQI 40
Frequently Asked Questions
How many unhealthy air days does Nogales, AZ have? ▼
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What does AQI 49 mean for health? ▼
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What is the 90th percentile AQI for Nogales, AZ? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset for Nogales, AZ, 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, Nogales, AZ · 2020–2025