Median AQI
32
Good
Hawaii · County air quality · 2025
Hawaii County, Hawaii
Median AQI 32 (Good). 86.0% of monitored days rated Good, direct from EPA Air Quality System stations.
- 32
- Median AQI
- 86.0%
- Good-air days
- 0
- Unhealthy days
- 72%
- Cleaner than US counties
Hawaii County's 2025 annual median AQI is 32 (Good), with 86.0% Good days
According to the U.S. EPA Air Quality System, Hawaii County, Hawaii posted a 2025 median AQI of 32 (Good) across 365 monitored days, with 86.0% rated Good and 0 unhealthy or worse. This is an annual comparison, not today's advisory.
Data source EPA Air Quality System (AQS)
- Cleaner than US
- Hawaii County's 86.0% Good-day share places it cleaner than 72% of US counties in 2025.
- Closest median-AQI peer
- Aroostook County (83.3% Good, median AQI 32) is the closest nationwide median-AQI peer to Hawaii County.
- 2020–2025 trend
- Hawaii County's floor-qualifying Good-day share is worsening from 2020 to 2025 (96.2% → 86.0%).
- Median AQI
- Median AQI: 32
The verdict
According to EPA Air Quality System monitoring data, Hawaii County's air is good on balance, cleaner than the median US county, a median AQI of 32 with 86.0% of 365 monitored days in the Good band, driven mainly by PM2.5.
- 32
- median AQI · Good
- 86.0%
- days rated Good
- PM2.5
- main pollutant
- 72%
- cleaner than US counties
Not one day crossed into the Unhealthy tier; the worst single reading was AQI 93.
Annual release change
What changed in the 2025 EPA annual release
- Hawaii County's Good-day share fell from 97.0% to 86.0% between the 2024 and 2025 EPA annual releases, a change of -11.0 percentage points.
- Hawaii County's median AQI rose from 21 to 32 between the 2024 and 2025 EPA annual releases, a change of +11 points.
- Hawaii County's peak single-day AQI rose from 75 to 93 between the 2024 and 2025 EPA annual releases, a change of +18 points.
Data updated August 2026
- Good · 314 d · 86.0%
- Moderate · 51 d · 14.0%
How did Hawaii County's air break down in 2025?
Across 365 monitored days, 314 fell in the Good band (AQI 0–50) and 0 reached Unhealthy or worse. The worst single day peaked at AQI 93 (Moderate).
EPA AQS →Air quality data from EPA Air Quality System (2025). 365 days monitored. Median AQI: 32 (Good).
Insights: Hawaii County, Hawaii. EPA monitors recorded a median Air Quality Index of 32 across 365 measured days in 2025, earning a Good classification and a Good health grade. Of those days, 314 (86%) fell in the Good band (AQI 0–50), 51 (14%) registered Moderate readings, and 0 (0%) reached Unhealthy for Sensitive Groups. The 90th-percentile AQI settled at 53, while the worst single-day peak hit 93 (Moderate). Residents averaged about 25.8 clean-air days per 30-day window during the monitoring year.
The full pollutant mix ranks as PM2.5 (365 days). Across the 2020–2025 trend window, the share of monitored days rated Good shifted by -10.1 points and the median AQI moved +9 points, placing the multi-year trajectory at worsening. The worst single reading over the 2020–2025 window was AQI 93, moderate but never Unhealthy. Nearby counties show comparable readings: Honolulu (97.3% good, AQI 29); Maui (98.1% good, AQI 21).
Air Quality Summary
Good Days
86.0%
314 of 365 monitored days
11.0pp vs 75% target
Max AQI Recorded
93
Moderate
Health Grade
Good
90th-pct AQI 53
Hawaii County, Good days share 86.0%
National avg
Share of monitored days at AQI 0-50 (Good band).
Hawaii County, Unhealthy-or-worse share 0.0%
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
314
86%
Moderate
51
14%
USG
0
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Pollutant Breakdown
Days where each pollutant was the primary driver of AQI readings in Hawaii County.
- PM2.5 · 365 days · 100.0%
Health Impact Assessment
Good
Hawaii County's air quality is rated Good based on 86.0% good air days. No unhealthy air days were recorded in 2025.
Air quality was acceptable on 86.0% of monitored days in 2025, with a median AQI of 32. Unusually sensitive people can check real-time conditions at AirNow.gov during high-pollution events.
The dominant pollutant is PM2.5, driving AQI on 365 of 365 monitored days.
5-Year Air Quality Trend
Air quality is worsening in Hawaii County. Highest Good-day share: 2024 (97.0%, 355 of 366 monitored days).
| Year | Good | Moderate | USG | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|---|
| 2020 | 352 | 14 | 0 | 0 | 23 | 83 |
| 2021 | 336 | 29 | 0 | 0 | 27 | 65 |
| 2022 | 328 | 37 | 0 | 0 | 33 | 71 |
| 2023 | 336 | 29 | 0 | 0 | 23 | 71 |
| 2024 | 355 | 11 | 0 | 0 | 21 | 75 |
| 2025 | 314 | 51 | 0 | 0 | 32 | 93 |
How does Hawaii County compare?
How Hawaii County compares
Good-day share better than typical
Hawaii County 86.0%
Aroostook County, Maine 83.3%
Typical US county 76.0%
Median AQI better than typical
Hawaii County 32
Aroostook County, Maine 32
Typical US county 39
Unhealthy days / yr better than typical
Hawaii County 0
Aroostook County, Maine 0
Typical US county 1
Counties with a similar median AQI
Nationwide peers within about the same annual median AQI as Hawaii County (32), not geographic neighbors.
Aroostook County, Maine
Median AQI 32 · 83.3% Good-day share
Belknap County, New Hampshire
Median AQI 32 · 88.8% Good-day share
Carter County, Oklahoma
Median AQI 32 · 81.6% Good-day share
Del Norte County, California
Median AQI 32 · 81.8% Good-day share
Macon County, North Carolina
Median AQI 32 · 96.5% Good-day share
Montgomery County, Tennessee
Median AQI 32 · 83.8% Good-day share
Same primary pollutant: PM2.5
PM2.5 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).
Bayamon County, Puerto Rico
86.0% Good-day share · median AQI 29
Norfolk City County, Virginia
86.0% Good-day share · median AQI 33
Lake County, Minnesota
85.9% Good-day share · median AQI 31
Wasco County, Oregon
86.3% Good-day share · median AQI 25
Delta County, Colorado
85.7% Good-day share · median AQI 29
Wyoming County, Pennsylvania
86.5% Good-day share · median AQI 24
Hawaii counties on the map
Geographic containment only, other monitored counties in Hawaii, independent of AQI or pollutant match.
What Hawaii County's air means for you
The air here stays in the breathable range year-round, with PM2.5 the main thing to watch.
- Sensitive groups (asthma, heart conditions, children, older adults) should check the AQI on high-PM2.5 days, the guide explains what a median of 32 means for exposure. Health guidance
- See how Hawaii County ranks against every monitored U.S. county on Good-day share. County rankings
- Compare Hawaii County with its Hawaii neighbours before drawing a conclusion about the region. All of Hawaii
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 Hawaii County, Hawaii? ▼
Hawaii County has a median Air Quality Index (AQI) of 32, rated "Good." 86.0% of monitored days (314 out of 365) had good air quality in 2025.
What is the main pollutant in Hawaii County? ▼
The primary pollutant in Hawaii County is Fine Particles (PM2.5), which was the main AQI driver on 365 days (100% of monitored days). Penetrates deep into lungs and bloodstream. Linked to heart disease and premature death.
How many unhealthy air days does Hawaii County have? ▼
In 2025, Hawaii County recorded 0 unhealthy air days (0 Unhealthy, 0 Very Unhealthy, 0 Hazardous). The maximum AQI reached 93.
Is the air quality in Hawaii County getting better or worse? ▼
Air quality in Hawaii 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: 2024 at 97.0% (355 of 366 days). Lowest qualifying Good-day share: 2025 at 86.0% (314 of 365 days).
What does AQI 32 mean for health? ▼
Hawaii County's median AQI of 32 falls in the "Good" category. See the AQI category guide for what each range means for health.
How does Hawaii County compare to other counties in Hawaii? ▼
Hawaii County has 86.0% good air days. Nearby counties in Hawaii: Honolulu (97.3% good), Maui (98.1% good).
What is the 90th percentile AQI in Hawaii County? ▼
The 90th percentile AQI for Hawaii County is 53, meaning 90% of monitored days had an AQI at or below this level. The maximum AQI recorded was 93 (Moderate).
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 Hawaii County, Hawaii · 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.