September weather forecastWailua, HI
September
Weather in September
September in Wailua brings mild changes compared to preceding months, with weather conditions staying comfortably warm and inviting. However, September experiences a reduction in rainfall to 1.54" (39mm), giving it a drier feel compared to the more humid August. Even as the later months of the year unfold, Wailua’s tropical appeal continues to charm its inhabitants and visitors. Breezy days and calm nights - typical of a tropical climate - make it soothing for both body and mind. As September hands the baton over to October, the seamless continuity in the climate pattern ensures a pleasant shift.Temperature
Wailua registers the highest average temperatures during the month of September, with peaks of 79.7°F (26.5°C) and lows of 75.9°F (24.4°C).Humidity
In September, the average relative humidity is 76%.Rainfall
In Wailua, in September, it is raining for 18.7 days, with typically 1.54" (39mm) of accumulated precipitation. Throughout the year, there are 218.4 rainfall days, and 22.13" (562mm) of precipitation is accumulated.Ocean temperature
The month with the warmest seawater in Wailua, Hawaii, is September, with an average ocean temperature of 80.2°F (26.8°C).Note: For activities in the water such as swimming or diving, temperatures from 77°F (25°C) to 84.2°F (29°C) are considered optimal for prolonged enjoyment without discomfort.
Daylight
The average length of the day in September is 12h and 16min.On the first day of the month, sunrise is at 6:20 am and sunset at 6:53 pm. On the last day of September, sunrise is at 6:28 am and sunset at 6:25 pm HST.
Sunshine
In Wailua, the average sunshine in September is 8.7h.UV index
The month with the highest UV index in Wailua is September, with an average maximum UV index of 7. A UV Index reading of 6 to 7 represents a high health risk from exposure to the Sun's UV radiation for the average person.Note: The UV index of 7 in September translates into these instructions:
Use protective steps and abide by sun safety guidelines. Safeguarding against skin and eye harm is necessary. Limit direct sun exposure especially between 10 a.m. and 4 p.m., when UV radiation is at its peak. However, keep in mind that shade structures may not provide full sun protection. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance. Heads up! UV intensity is amplified by reflections from water and sand.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Wailua, HI
- Average high temperature in September: 79.7°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 September: 75.9°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 September
Wailua, HI
- Average pressure in September: 29.98"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 September
Wailua, HI
- Average wind speed in September: 11.1mph
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 September
Wailua, HI
- Average humidity in September: 76%
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 September
Wailua, HI
- Average rainfall in September: 1.54"
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 September
Wailua, HI
- Average rainfall days in September: 18.7 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 September
Wailua, HI
- Average sea temperature in September: 80.2°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 September /
Average sunshine in September
Wailua, HI
- Average daylight in September: 12h and 18min
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 September: 8h and 42min
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 September
Wailua, HI
- Average sunshine days in September: 5.3 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 September
Wailua, HI
- Average UV index in September: 7
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 September
Wailua, HI
- Average cloud cover in September: 38
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 September
Wailua, 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).
