Metro area air quality · 2025
Urban Honolulu, HI
Median AQI 29 (Good). 97.3% of monitored days rated Good across this metro's EPA monitoring network.
- 29
- Median AQI
- 97.3%
- Good-air days
- 0
- Unhealthy days
- 97%
- Cleaner than US metros
Urban Honolulu, HI posted a 2025 median AQI of 29 (Good) with 97.3% Good days
According to the U.S. EPA Air Quality System, the Urban Honolulu, HI CBSA recorded a median AQI of 29 across 365 monitored days in 2025, with 97.3% 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 Urban Honolulu, HI CBSA's 97.3% Good-day share places it cleaner than 97% of US metros in 2025.
- Closest median-AQI peer
- Port Angeles, WA (85.5% Good, median AQI 29) is the closest nationwide median-AQI peer to Urban Honolulu, HI.
- 2020–2025 Good-day shift
- Urban Honolulu, HI's Good-day share moved -1.9 points from 2020 to 2025 (median AQI +1).
- Median AQI
- Median AQI: 29
Aggregated from EPA Air Quality System (2025), 365 monitored days. EPA AQS →
The verdict
The Urban Honolulu, HI metro runs good on the EPA scale, among the cleanest 10% of US metros, a median AQI of 29 with 97.3% of 365 monitored days in the Good band.
- 29
- median AQI · Good
- 97.3%
- days rated Good
- 97%
- cleaner than US metros
- 59
- 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
- Urban Honolulu, HI metro's peak single-day AQI fell from 85 to 59 between the 2024 and 2025 EPA annual releases, a change of -26 points.
- Urban Honolulu, HI metro's Good-day share fell from 98.4% to 97.3% between the 2024 and 2025 EPA annual releases, a change of -1.1 percentage points.
Insights: Urban Honolulu, HI metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 29 over 365 measured days in 2025, which corresponds to a Good band and a Excellent metro-wide health grade. The monitored-day split lands at 355 Good days (97%), 10 Moderate (3%), and 0 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 39 while the highest single-day reading hit 59 (Moderate). Metro residents averaged roughly 29.2 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 -1.9 points and the median AQI moved +1 points, which classifies the multi-year trajectory as stable. The metro recorded no Unhealthy-tier days in this annual dataset. Metros with comparable AQI profiles include Port Angeles, WA (85.5% good, AQI 29); Butte-Silver Bow, MT (84.9% good, AQI 28); Cookeville, TN (90.0% good, AQI 30).
Air Quality Summary
Median AQI
29
Good
Good Days
97.3%
355 of 365 days
Max AQI
59
Moderate
Health Grade
Excellent
90th pct: 39
AQI Day Breakdown (2025)
Distribution of 365 monitored days across EPA AQI categories.
Good
355
97%
Moderate
10
3%
USG
0
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Urban Honolulu, HI metro area's air quality is rated Excellent based on 97.3% 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 Urban Honolulu, HI metro compare?
How Urban Honolulu, HI compares
5-Year Air Quality Trend
Air quality is stable in the Urban Honolulu, HI metro. Highest Good-day share: 2021 (99.7%, 364 of 365 monitored days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 363 | 3 | 0 | 28 | 63 |
| 2021 | 364 | 1 | 0 | 28 | 58 |
| 2022 | 356 | 9 | 0 | 29 | 57 |
| 2023 | 337 | 27 | 0 | 31 | 117 |
| 2024 | 360 | 6 | 0 | 31 | 85 |
| 2025 | 355 | 10 | 0 | 29 | 59 |
Metros with a similar median AQI
CBSA peers nationwide whose annual median AQI sits near Urban Honolulu, HI (29).
Port Angeles, WA
Median AQI 29 · 85.5% Good-day share
Butte-Silver Bow, MT
Median AQI 28 · 84.9% Good-day share
Cookeville, TN
Median AQI 30 · 90.0% Good-day share
Dodge City, KS
Median AQI 28 · 89.8% Good-day share
Lynchburg, VA
Median AQI 30 · 85.2% Good-day share
Moses Lake, WA
Median AQI 28 · 79.7% Good-day share
Metros with similar unhealthy-day exposure
A second relationship type: metros whose unhealthy-or-worse day count is closest to Urban Honolulu, HI's 0 (independent of median AQI).
Aberdeen, SD
0 unhealthy-or-worse days · median AQI 27
Aberdeen, WA
0 unhealthy-or-worse days · median AQI 22
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
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 Urban Honolulu, HI metro area? ▼
How many unhealthy air days does Urban Honolulu, HI have? ▼
Is air quality in Urban Honolulu, HI getting better or worse? ▼
What does AQI 29 mean for health? ▼
What is the 90th percentile AQI for Urban Honolulu, HI? ▼
How does Urban Honolulu, HI 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.