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
Waimalu's warmest months, August and September, record an average high-temperature of 82°F (27.8°C).Heat index
September's mean heat index is calculated to be a tropical 87.8°F (31°C). With ongoing exposure and activity, one might experience weariness, and heat cramps could ensue.Bear in mind that the heat index values are determined for shaded areas and light breezes. Direct sunlight might lead to a heat index increase by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', provides an understanding of perceived warmth by combining temperature and relative humidity. The influence of weather is personal, with varied individuals experiencing it differently due to differences in body mass, stature, and physical exertion levels. When directly under the sun, the weather's impact can intensify, possibly boosting the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. Kids frequently ignore the importance of taking a break and rehydrating. Thirst is a late symptom of dehydration - thus, it is crucial to stay hydrated, especially during long-lasting physical activities.
Humidity
April through June and September, with an average relative humidity of 74%, are the least humid months.Rainfall
In Waimalu, in September, during 19.5 rainfall days, 1.46" (37mm) of precipitation is typically accumulated. Throughout the year, there are 208.4 rainfall days, and 16.5" (419mm) of precipitation is accumulated.Ocean temperature
The months with the warmest seawater are August through October, with an average ocean temperature of 80.6°F (27°C).Note: Surface water temperatures falling between 77°F (25°C) and 84.2°F (29°C) are regarded as prime and extremely agreeable for enduring periods during any water activity.
Daylight
In Waimalu, the average length of the day in September is 12h and 15min.On the first day of the month, sunrise is at 6:15 am and sunset at 6:47 pm. On the last day of September, sunrise is at 6:22 am and sunset at 6:19 pm HST.
Sunshine
In September, the average sunshine is 8.4h.UV index
September is the month with the highest UV index, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: In September, the UV index of 7 transforms into the following advice:
Stay clear of intense sun exposure. Solar protection is of utmost significance. The time between 10 a.m. and 4 p.m. is when UV radiation is at its peak. Limit exposure to direct sunlight during these hours. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes. Attention! UV strength is notably upped by the reflection of sand and water.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the hottest time of year?
What are the temperatures in September?
What are the least humid months?
What is the average humidity in September?
How many days does it rain in September?
What months are the ocean warmest?
How warm is the water in September?
What is the average length of the day in September?
When are sunrise and sunset in September?
How many hours of sunshine does Waimalu have in September?
When is the highest UV index?
What is the UV index intensity in September?
Average temperature in September
Waimalu, HI
- Average high temperature in September: 82°F
The warmest months (with the highest average high temperature) are August and September (82°F).
The months with the lowest average high temperature are February and March (75.4°F).
- Average low temperature in September: 75°F
The month with the highest average low temperature is September (75°F).
The coldest month (with the lowest average low temperature) is February (68°F).
Average pressure in September
Waimalu, HI
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is April (30.06"Hg).
The months with the lowest atmospheric pressure are September and October (29.97"Hg).
Average wind speed in September
Waimalu, HI
- Average wind speed in September: 9.3mph
The windiest month (with the highest average wind speed) is July (11.3mph).
The calmest month (with the lowest average wind speed) is January (8.4mph).
Average humidity in September
Waimalu, 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 April, May, June and September (74%).
Average rainfall in September
Waimalu, HI
- Average rainfall in September: 1.46"
The wettest month (with the highest rainfall) is October (2.09").
The driest month (with the least rainfall) is July (0.71").
Average rainfall days in September
Waimalu, HI
- Average rainfall days in September: 19.5 days
The month with the highest number of rainy days is March (20 days).
The month with the least rainy days is January (13.5 days).
Average sea temperature in September
Waimalu, HI
- Average sea temperature in September: 81°F
The best months for swimming (with the highest average sea temperature) are August, September and October (81°F).
The coldest months (with the lowest average sea temperature) are January, February, March and April (75°F).
Average daylight in September /
Average sunshine in September
Waimalu, 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 54min).
- Average sunshine in September: 8h and 2min
The month with the most sunshine is June (Average sunshine: 9h and 54min).
The months with the least sunshine are November and December (Average sunshine: 6h and 18min).
Average sunshine days in September
Waimalu, HI
- Average sunshine days in September: 6.5 days
The month with the most sunshine days is January (12.3 days).
The month with the least sunshine days is November (6.2 days).
Average UV index in September
Waimalu, 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
Waimalu, HI
- Average cloud cover in September: 38
The month with the most cloud cover is March (Cloud cover 44).
The month with the least cloud cover is January (Cloud cover 36).
Average visibility in September
Waimalu, 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).
Waimalu, Hawaii, USA
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