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).

23
Median AQI
Good
0.0%
Days above AQI 100
0 of 217 days
32
90th percentile AQI
worst 1 day in 10
73
Peak AQI
Moderate
PM2.5
Main pollutant
64.5% of days
98.2%
Good days
213 of 217
  • Good: 98.2%
  • Moderate: 1.8%
  • Unhealthy for Sensitive Groups: 0.0%
  • Unhealthy or worse: 0.0%

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QUICK ANSWER

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)

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
20193123037O3
2020cleanest3119032PM2.5
20213123043O3
20223122033PM2.5
2023worst3131073PM2.5
20243124052PM2.5
20253122030PM2.5

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 15 (PM2.5). 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.