September weather forecastKeauhou, HI
September
Weather in September
September, the first month of the autumn in Keauhou, is also an agreeable month, with temperature in the range of an average high of 73°F (22.8°C) and an average low of 69.8°F (21°C).Temperature
Keauhou's shift from August to September is accompanied by an average high-temperature of a still agreeable 73°F (22.8°C), a slight deviation from 73.2°F (22.9°C). In September, Keauhou's nights cool slightly to a consistent average temperature of 69.8°F (21°C).Humidity
June through September, with an average relative humidity of 81%, are the most humid months.Rainfall
The month with the most rainfall is September, when the rain falls for 21.5 days and typically aggregates up to 1.81" (46mm) of precipitation.Ocean temperature
The month with the warmest seawater is September, with an average ocean temperature of 80.1°F (26.7°C).Note: For engaging in water activities including swimming and diving, temperatures from 77°F (25°C) to 84.2°F (29°C) are perceived as perfect, providing pleasure for extended durations.
Daylight
The average length of the day in September is 12h and 14min.On the first day of September, sunrise is at 6:08 am and sunset at 6:38 pm. On the last day of the month, sunrise is at 6:14 am and sunset at 6:12 pm HST.
Sunshine
The average sunshine in September is 8.7h.UV index
May through October, with an average maximum UV index of 6, are months with the highest UV index. A UV Index estimate of 6 to 7 represents a high health vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: A maximum UV index of 6 in September translates into the following recommendations:
Persist with precautions and heed sun safety advice. Prevention of sunburn is compulsory. Between 10 a.m. and 4 p.m., UV radiation is strongest. Make an effort to avoid direct sunlight during this time, remembering that shade structures may not provide full sun protection. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days. Take note! Sand and water reflections strengthen the Sun's UV exposure.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Keauhou, HI
- Average high temperature in September: 73°F
The warmest months (with the highest average high temperature) are August and October (73.2°F).
The month with the lowest average high temperature is February (68.9°F).
- Average low temperature in September: 69.8°F
The month with the highest average low temperature is October (70°F).
The coldest month (with the lowest average low temperature) is March (64.8°F).
Average pressure in September
Keauhou, HI
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is April (30.04"Hg).
The months with the lowest atmospheric pressure are September and October (29.96"Hg).
Average wind speed in September
Keauhou, HI
- Average wind speed in September: 6.2mph
The windiest month (with the highest average wind speed) is May (6.3mph).
The calmest month (with the lowest average wind speed) is December (5.3mph).
Average humidity in September
Keauhou, HI
- Average humidity in September: 81%
The months with the highest relative humidity are June, July, August and September (81%).
The month with the lowest relative humidity is February (73%).
Average rainfall in September
Keauhou, HI
- Average rainfall in September: 1.81"
The wettest month (with the highest rainfall) is September (1.81").
The driest month (with the least rainfall) is January (0.75").
Average rainfall days in September
Keauhou, HI
- Average rainfall days in September: 21.5 days
The month with the highest number of rainy days is August (21.8 days).
The month with the least rainy days is January (10.8 days).
Average sea temperature in September
Keauhou, HI
- Average sea temperature in September: 80°F
The best month for swimming (with the highest average sea temperature) is September (80°F).
The coldest month (with the lowest average sea temperature) is March (76°F).
Average daylight in September /
Average sunshine in September
Keauhou, HI
- Average daylight in September: 12h and 12min
The month with the longest days is June (Average daylight: 13h and 18min).
The month with the shortest days is December (Average daylight: 11h and 0min).
- Average sunshine in September: 8h and 42min
The month with the most sunshine is May (Average sunshine: 10h and 42min).
The months with the least sunshine are November and December (Average sunshine: 7h and 18min).
Average sunshine days in September
Keauhou, HI
- Average sunshine days in September: 3.5 days
The month with the most sunshine days is January (12.7 days).
The month with the least sunshine days is May (3.2 days).
Average UV index in September
Keauhou, HI
- Average UV index in September: 6
The months with the highest UV index are May, June, July, August, September and October (UV index 6).
The months with the lowest UV index are January, February, March, April, November and December (UV index 5).
Average cloud cover in September
Keauhou, HI
- Average cloud cover in September: 28
The month with the most cloud cover is June (Cloud cover 31).
The month with the least cloud cover is January (Cloud cover 15).
Average visibility in September
Keauhou, HI
- Average visibility in September: 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).
