Kapaa, Kauai weather in August
Temperature, sea and sunshine in August: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in August
Excellent
Best time to visit: January – December
What is the weather like in Kapaa, Kauai in August?
In August, Kapaa, Kauai is hot: daytime highs average 27 °C, and even at night it stays warm at around 24 °C. The sea averages 26.4 °C – lovely and warm for swimming. The sun shines for around 9 hours a day. Rain is frequent, with about 14 rainy days and 41 mm in total. The air is often humid and muggy. All in all, August is an excellent month for a holiday in Kapaa, Kauai.
August compared
How the weather changes from July to September. Tap a month to open it.
| JulyJul | AugustAug | SeptemberSep | |
|---|---|---|---|
| Score | 84 | 85 | 83 |
| Day | 27° | 27° | 27° |
| Night | 23° | 24° | 24° |
| Sea | 26° | 26° | 27° |
| Sun | 9 h | 9 h | 8 h |
| Rain days | 15 | 14 | 14 |
More details for August
- Daylight
- 12 h 55 min06:15 – 19:10
- UV index
- 12 · extremeclear sky, noon (estimate)All months
- Muggy days
- 31 daysdew point 18 °C or moreAll months
- Wind
- 16 km/haverage daily peakAll months
- Cloud cover
- 45 %on averageAll months
- Hot days
- 0 days30 °C or moreAll months
- Time zone
- UTC−10Pacific/Honolulu
How the score comes together
- Temperatureweight 35 %100 %
- Seaweight 25 %100 %
- Sunshineweight 20 %95 %
- Few rainy daysweight 20 %31 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Sun, sea & sand”.
What to pack in August
- Swimwear
- Sunscreen
- Sunglasses & sun hat
- Light, breathable clothes
- Insect repellent
- Rain jacket or umbrella
Kapaa, Kauai in August: quick answers
Is Kapaa, Kauai hot in August?
Yes. In August, Kapaa, Kauai is hot: daytime highs average 27 °C and nights stay around 24 °C.
Can you swim in Kapaa, Kauai in August?
Yes. In August the sea averages 26.4 °C – lovely and warm for swimming.
Does it rain much in Kapaa, Kauai in August?
Rain is frequent, with about 14 rainy days and 41 mm in total.
Kapaa, Kauai month by month
The whole year in Kapaa, KauaiAll destinations: USAHawaii weather in AugustWhere to go in AugustSea temperature in August
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences