Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average sea temperature in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
September, known for its average high temperature of 81.7°F (27.6°C) and an average low temperature of 75.7°F (24.3°C), is the warmest month.Heat index
September's average heat index is estimated at a tropical 86°F (30°C). With prolonged exposure and constant activity, one might feel exhausted and experience heat cramps.Heat index guidelines indicate values are for light wind scenarios and shaded regions. The heat index could see an increase by 15 Fahrenheit (8 Celsius) degrees under direct sunshine.
Note: The heat index, also known as 'apparent temperature' or 'feels like', stands as a testimony to how temperature and humidity combine to impact our sense of warmth. Metabolic differences, pregnancy status, and the level of physical activity are additional factors influencing an individual's weather perception. It is essential to be conscious of the fact that direct sunlight can intensify the felt heat, leading to an elevation in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for babies and toddlers. Children frequently underestimate the necessity to rest and hydrate. Thirst is a late sign of dehydration - thus, it is vital to stay hydrated, particularly during lengthy physical exercises.
Humidity
The months with the lowest humidity are May and September, with an average relative humidity of 74%.Rainfall
In September, in Waialua, the rain falls for 17.4 days. Throughout September, 0.98" (25mm) of precipitation is accumulated. In Waialua, during the entire year, the rain falls for 190.2 days and collects up to 11.65" (296mm) of precipitation.Ocean temperature
The month with the warmest seawater is September, with an average ocean temperature of 80.2°F (26.8°C).Note: Water activities including swimming and diving at temperatures from 77°F (25°C) to 84.2°F (29°C) are deemed very pleasurable and enjoyable for extended periods, devoid of discomfort.
Daylight
The average length of the day in September is 12h and 16min.On the first day of September, sunrise is at 6:16 am and sunset at 6:48 pm. On the last day of the month, sunrise is at 6:23 am and sunset at 6:20 pm HST.
Sunshine
In September, the average sunshine in Waialua is 8.6h.UV index
The months with the highest UV index are July and September, with an average maximum UV index of 7. A UV Index estimate of 6 to 7 represents a high health vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum UV index of 7 during September translates into these guidelines:
Use protective steps and abide by sun safety guidelines. Safeguarding against skin and eye harm is necessary. Stay in the shade and avoid direct Sun exposure from 10 a.m. to 4 p.m., a period when UV radiation is particularly strong, noting that parasols or canopies may not offer total sun protection. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration. Caution! Sand and water surfaces escalate the UV intensity from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What part of the year is the hottest?
What are September temperatures?
What are the least humid months?
What is the average humidity in September?
How much does it rain in September?
When is the ocean warmest?
What is the ocean temperature in September?
How many hours of daylight does Waialua have in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the month with the highest UV index in Waialua?
What is the UV index reading in September?
Average temperature in September
Waialua, HI
- Average high temperature in September: 81.7°F
The warmest month (with the highest average high temperature) is September (81.7°F).
The month with the lowest average high temperature is February (75°F).
- Average low temperature in September: 75.7°F
The months with the highest average low temperature are August and September (75.7°F).
The coldest month (with the lowest average low temperature) is February (68.5°F).
Average pressure in September
Waialua, HI
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is April (30.06"Hg).
The month with the lowest atmospheric pressure is October (29.97"Hg).
Average wind speed in September
Waialua, HI
- Average wind speed in September: 9.8mph
The windiest month (with the highest average wind speed) is July (11.6mph).
The calmest month (with the lowest average wind speed) is January (9mph).
Average humidity in September
Waialua, HI
- Average humidity in September: 74%
The months with the highest relative humidity are February and December (76%).
The months with the lowest relative humidity are May and September (74%).
Average rainfall in September
Waialua, HI
- Average rainfall in September: 0.98"
The wettest months (with the highest rainfall) are February and October (1.34").
The driest month (with the least rainfall) is July (0.63").
Average rainfall days in September
Waialua, HI
- Average rainfall days in September: 17.4 days
The month with the highest number of rainy days is March (17.7 days).
The month with the least rainy days is January (12.5 days).
Average sea temperature in September
Waialua, 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 (75.2°F).
Average daylight in September /
Average sunshine in September
Waialua, HI
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 13h and 24min).
The month with the shortest days is December (Average daylight: 10h and 48min).
- Average sunshine in September: 8h and 4min
The month with the most sunshine is June (Average sunshine: 9h and 54min).
The month with the least sunshine is November (Average sunshine: 6h and 12min).
Average sunshine days in September
Waialua, HI
- Average sunshine days in September: 6.5 days
The month with the most sunshine days is January (12.9 days).
The month with the least sunshine days is September (6.5 days).
Average UV index in September
Waialua, HI
- Average UV index in September: 7
The months with the highest UV index are July and September (UV index 7).
The months with the lowest UV index are January, February, March, April, May, June, August, October, November and December (UV index 6).
Average cloud cover in September
Waialua, HI
- Average cloud cover in September: 37
The month with the most cloud cover is March (Cloud cover 44).
The months with the least cloud cover are January and September (Cloud cover 37).
Average visibility in September
Waialua, 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).
Waialua, Hawaii, USA
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