Honolulu, Hawaii Air Quality Today
AirHistory tracks long-run EPA monitoring rather than live readings, so for the live number check AirNow.gov below. As a baseline, Honolulu, Hawaii's most recent EPA year (2023) posted a median AQI of 31 (Good) against a 5-year median of 29 and an overall Grade of B. The dominant pollutant is Ground-Level Ozone, which tells you which days are most likely to spike.
Check Today's Live AQI in Honolulu, Hawaii
AirHistory is built on 10 years of EPA Air Quality System records, so it shows you what air quality in Honolulu, Hawaii typically looks like — not the live reading for this exact hour. For today's real-time AQI, check AirNow.gov (the EPA's official live index) or the AirNow Fire and Smoke Map during wildfire season.
That said, the history is the best predictor of a normal day. In 2023, Honolulu, Hawaii posted a median AQI of 31 (Good), with 337 "Good" days and 1 days that crossed into "Unhealthy for Sensitive Groups" or worse. The dominant pollutant, Ground-Level Ozone, is the one most likely to push today's number up — Ground-level ozone forms when sunlight reacts with vehicle exhaust and industrial emissions. It is worst on hot, sunny, stagnant summer days. Ozone irritates the lungs, triggers asthma attacks, and reduces lung function — even healthy adults can feel chest tightness and shortness of breath after exercising in elevated ozone.
Honolulu, Hawaii Air Quality Snapshot
| Air Quality Grade | B76/100 |
| 5-Year Median AQI | 29 (Good) |
| Most Recent Median AQI (2023) | 31 (Good) |
| Dominant Pollutant | Ground-Level Ozone |
| 10-Year Trend | Improving (-0.69 AQI/yr) |
| Unhealthy Days (last 5 yr) | 1 |
| National Rank (cleanest = #1) | #119 of 1,020 (12th cleanest percentile) |
| Hawaii Rank | #4 of 4 |
What Does the B Grade Mean?
Honolulu, Hawaii earns a B — air quality is reliably in the safe range for most residents most of the time, with a 5-year median AQI of 29. Sensitive groups will see occasional caution days, but the typical resident will not need to change behavior based on air quality.
Honolulu, Hawaii's 5-year median AQI of 29 is 12 points below the national average of 41 — meaningfully cleaner than the typical U.S. metro tracked here. Within Hawaii, Honolulu, Hawaii runs more polluted than the state average of 23 — local sources or geography are concentrating pollution above the state's typical reading.
For context within Hawaii: Hawaii, Hawaii currently holds the state's cleanest grade (A, AQI 25), while Kauai, Hawaii sits at the bottom (A, AQI 15).
What's in Honolulu, Hawaii's Air?
The dominant pollutant in Honolulu, Hawaii is Ground-Level Ozone. Ground-level ozone forms when sunlight reacts with vehicle exhaust and industrial emissions. It is worst on hot, sunny, stagnant summer days. Ozone irritates the lungs, triggers asthma attacks, and reduces lung function — even healthy adults can feel chest tightness and shortness of breath after exercising in elevated ozone.
Days by Dominant Pollutant (2023)
| Pollutant | Days as Dominant | Share of Year |
|---|---|---|
| Fine Particulate Matter (PM2.5) | 187 | 51% |
| Ground-Level Ozone | 174 | 48% |
| Coarse Particulate Matter (PM10) | 4 | 1% |
Is the Air Getting Better or Worse?
Air quality in Honolulu, Hawaii has been improving over the past decade, with median AQI dropping by roughly 0.7 points per year. That is consistent with the broader national pattern — most U.S. metros have seen steady reductions in particulate and ozone pollution since the 2010s as cleaner vehicles and power plants come online.
In 2014, Honolulu, Hawaii posted a median AQI of 32. By 2023 that figure was 31 — a drop of 1 AQI points cleaner across 10 years of EPA records.
Year-by-Year AQI in Honolulu, Hawaii
| Year | Median AQI | Good Days | Unhealthy Days | Dominant Pollutant |
|---|---|---|---|---|
| 2014 | 32 | 325 | 1 | PM2.5 |
| 2015 | 39 | 283 | 0 | PM2.5 |
| 2016 | 32 | 330 | 0 | Ozone |
| 2017 | 32 | 340 | 0 | Ozone |
| 2018 | 31 | 353 | 0 | Ozone |
| 2019 | 28 | 360 | 0 | Ozone |
| 2020 | 28 | 363 | 0 | Ozone |
| 2021 | 28 | 364 | 0 | Ozone |
| 2022 | 29 | 356 | 0 | PM2.5 |
| 2023 | 31 | 337 | 1 | PM2.5 |
Health Context for Honolulu, Hawaii
Across the past five years, this area has logged just 1 days where AQI rose into the "Unhealthy for Sensitive Groups" range or worse — about 0 days per year, or roughly one every other month. That is a low count by national standards.
For most healthy adults, current air quality in this area does not require any change in behavior. People with severe asthma, COPD, or recent cardiac events should still keep an eye on daily AQI alerts, especially during wildfire season. Because ozone peaks in the afternoon on hot sunny days, plan outdoor exercise for early morning or after sunset on bad-air days.
How This Grade Is Calculated
The AirHistory Air Quality Grade combines four signals: the 5-year median AQI (40% of the score), the 10-year trend direction (30%), the count of unhealthy days per year (20%), and the dominant pollutant type (10%). All four come directly from the EPA Air Quality System (AQS), which aggregates readings from federally certified monitors. Read the full methodology.
More about Honolulu, Hawaii
Honolulu, Hawaii has an Air Quality Grade of B (good) with a 5-year median AQI of 29. The dominant pollutant is Ground-Level Ozone, and air quality has been improving over the past decade.
The data source behind this answer is the EPA Air Quality System (AQS). Every figure on the page traces back to that source; the methodology page describes the inputs and the refresh cadence in full detail.
A practical caveat: the headline answer above reflects the most recent the EPA Air Quality System (AQS) vintage; underlying data is often revised for months after first publication, and the right reference for any specific decision is whichever vintage is current at the time of the decision. The as-of date is stamped on every page.
Source: EPA Outdoor Air Quality Data, 2026.