August weather forecastKapaa, HI
August
Weather in August
August in Kapaa, Hawaii continues the summer trend, with maximum temperatures peaking at 79.7°F (26.5°C) - the highest of the year. The enticing warm sea temperatures and the longer sunshine hours make outdoor activities irresistible. The cooling winds offer a much-needed counterbalance to the heat. The tropical scenery unfolds in its full glory, enchanting residents and tourists alike.Temperature
The shift into August uncovers an average high-temperature of a still moderately hot 79.5°F (26.4°C), subtly different from the previous month. A steady low-temperature average of 75.7°F (24.3°C) is logged during August, reflecting a modest dip from daytime readings.Humidity
June through August, October and December, with an average relative humidity of 77%, are the most humid months.Rainfall
In Kapaa, in August, it is raining for 21.1 days, with typically 1.89" (48mm) of accumulated precipitation. In Kapaa, during the entire year, the rain falls for 218.4 days and collects up to 22.13" (562mm) of precipitation.Ocean temperature
In Kapaa, in August, the average water temperature is 79.2°F (26.2°C).Note: Water surface temperatures from 77°F (25°C) to 84.2°F (29°C) are considered optimal and extremely delightful for long-lasting pleasure in any water activity.
Daylight
In Kapaa, the average length of the day in August is 12h and 52min.On the first day of August, sunrise is at 6:10 am and sunset at 7:17 pm. On the last day of the month, sunrise is at 6:20 am and sunset at 6:54 pm HST.
Sunshine
In August, the average sunshine is 8.4h.UV index
The months with the lowest UV index are January through August, October through December, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high health vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: The daily high UV index of 6 in August translates into this advice:
Sidestep overexposure. Individuals with fair complexions risk burning in fewer than 20 minutes. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. Opt for tightly woven and loose clothing to enhance protection from the Sun. Be attentive! The UV exposure is heightened with reflections from sand and water.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in August
Kapaa, HI
- Average high temperature in August: 79.5°F
The warmest month (with the highest average high temperature) is September (79.7°F).
The months with the lowest average high temperature are February and March (73.2°F).
- Average low temperature in August: 75.7°F
The month with the highest average low temperature is September (75.9°F).
The coldest month (with the lowest average low temperature) is February (68.5°F).
Average pressure in August
Kapaa, HI
- Average pressure in August: 30"Hg
The month with the highest atmospheric pressure is April (30.07"Hg).
The months with the lowest atmospheric pressure are September and October (29.98"Hg).
Average wind speed in August
Kapaa, HI
- Average wind speed in August: 12.1mph
The windiest month (with the highest average wind speed) is July (12.3mph).
The calmest month (with the lowest average wind speed) is January (10mph).
Average humidity in August
Kapaa, HI
- Average humidity in August: 77%
The months with the highest relative humidity are June, July, August, October and December (77%).
The month with the lowest relative humidity is January (75%).
Average rainfall in August
Kapaa, HI
- Average rainfall in August: 1.89"
The wettest month (with the highest rainfall) is March (2.52").
The driest month (with the least rainfall) is April (1.3").
Average rainfall days in August
Kapaa, HI
- Average rainfall days in August: 21.1 days
The month with the highest number of rainy days is August (21.1 days).
The month with the least rainy days is January (12.5 days).
Average sea temperature in August
Kapaa, HI
- Average sea temperature in August: 79.2°F
The best month for swimming (with the highest average sea temperature) is September (80.2°F).
The coldest month (with the lowest average sea temperature) is March (74.8°F).
Average daylight in August /
Average sunshine in August
Kapaa, HI
- Average daylight in August: 12h and 54min
The month with the longest days is June (Average daylight: 13h and 30min).
The month with the shortest days is December (Average daylight: 10h and 48min).
- Average sunshine in August: 8h and 24min
The month with the most sunshine is June (Average sunshine: 9h and 42min).
The month with the least sunshine is November (Average sunshine: 6h and 12min).
Average sunshine days in August
Kapaa, HI
- Average sunshine days in August: 2.9 days
The month with the most sunshine days is January (12.8 days).
The month with the least sunshine days is August (2.9 days).
Average UV index in August
Kapaa, HI
- Average UV index in August: 6
The month with the highest UV index is September (UV index 7).
The months with the lowest UV index are January, February, March, April, May, June, July, August, October, November and December (UV index 6).
Average cloud cover in August
Kapaa, HI
- Average cloud cover in August: 44
The month with the most cloud cover is March (Cloud cover 47).
The months with the least cloud cover are January and September (Cloud cover 38).
Average visibility in August
Kapaa, HI
- Average visibility in August: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





