Honolulu Air Quality in August
Across 2019–2025, Honolulu's August air quality had a median AQI of 23 (Good) over 217 monitored days in the Urban Honolulu, HI area. 0.0% of August days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 64.5% of days. The cleanest August on record here was 2020 (median AQI 19, 0 days above 100) and the worst was 2023 (median 31, 0 days above 100, peak AQI 73).
- Good: 98.2%
- Moderate: 1.8%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
Reduce Indoor Ozone in Honolulu
Today's main pollutant in Honolulu is ground-level ozone (AQI 28). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.
Recommended: Levoit Core 300 — True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft
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How is the air in Honolulu in August?
Good on a typical day: median AQI 23 across 2019–2025, with 0.0% of August days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓98.2% of August days were Good (AQI 0–50), 1.8% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the August peak was 73.
- ✓Best August: 2020; worst August: 2023.
Frequently asked questions
What is the air quality like in Honolulu in August?▾
Across 2019–2025, the median daily AQI in Honolulu in August was 23 (Good). 98.2% of days were Good, 1.8% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is August a good time for outdoor exercise in Honolulu?▾
A typical August day in Honolulu sits in the Good range (median AQI 23), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of August days reached AQI 101+ in 2019–2025.
Which pollutant causes Honolulu's August air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 64.5% of August days in Honolulu. The highest August AQI recorded in 2019–2025 was 73 (Moderate), in 2023.
Honolulu August air quality, year by year
Honolulu August air quality by year (Urban Honolulu, HI, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 23 | 0 | 37 | O3 |
| 2020cleanest | 31 | 19 | 0 | 32 | PM2.5 |
| 2021 | 31 | 23 | 0 | 43 | O3 |
| 2022 | 31 | 22 | 0 | 33 | PM2.5 |
| 2023worst | 31 | 31 | 0 | 73 | PM2.5 |
| 2024 | 31 | 24 | 0 | 52 | PM2.5 |
| 2025 | 31 | 22 | 0 | 30 | PM2.5 |
What August air means in Honolulu
A typical August day in Honolulu sits in the Good range (median AQI 23), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of August days reached AQI 101+ in 2019–2025.
August's median AQI of 23 is below Honolulu's whole-year median of 29, making it one of the area's cleaner periods. Nationally, the median August AQI across every EPA metro area (104,152 metro-days, 2019–2025) is 45, so Honolulu runs below the national August norm; 0.0% of its August days topped AQI 100 versus 3.5% nationally (below average).
August is part of Honolulu's summer season (June, July, August); the summer page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Honolulu
The latest EPA AirNow observation puts Honolulu's AQI at 28 (O3). The figures above are multi-year month statistics, not today's reading.
View current Honolulu air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Urban Honolulu, HI), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.