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, with its high-temperature average of 80.6°F (27°C) and a low-temperature average of 77°F (25°C), is the warmest month in Kailua.Heat index
The average heat index in September is appraised at 84.2°F (29°C). Fatigue might occur with continuous exposure and activity, potentially causing heat cramps.Heat index's context suggests values are appropriate for shady areas and slight breezes. The heat index could experience an increase of 15 Fahrenheit (8 Celsius) degrees due to direct sunlight.
Note: The heat index, also known as 'real feel' or 'felt air temperature', shows a temperature sensation when both heat and moisture conditions are combined. Elements such as metabolic variations, pregnancy, and physical exertion can influence one's weather perception. Recognize that direct exposure to the sun can escalate the heat effect, potentially adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are quite important for children. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
Humidity
In September, the average relative humidity is 75%.Rainfall
In September, in Kailua, Hawaii, the rain falls for 13 days. Throughout September, 0.94" (24mm) of precipitation is accumulated. In Kailua, during the entire year, the rain falls for 169.9 days and collects up to 13.15" (334mm) of precipitation.Ocean temperature
With an average ocean temperature of 80.4°F (26.9°C), September is the month with the warmest seawater in Kailua.Note: Between the temperatures of 77°F (25°C) and 84.2°F (29°C), water is considered very warm, providing pleasure in water activities without discomfort over lengthy periods.
Daylight
In September, the average length of the day is 12h and 15min.On the first day of the month, sunrise is at 6:14 am and sunset at 6:46 pm. On the last day of September, in Kailua, sunrise is at 6:22 am and sunset at 6:19 pm HST.
Sunshine
In Kailua, the average sunshine in September is 9.3h.UV index
The months with the highest UV index are July through October, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high health risk from unsafe exposure to UV radiation for the average person.Note: The daily high UV index of 7 in September translates into this advice:
Embrace precautions and observe sun safety norms. Evasion of sunburn is a necessity. Stay in the shade and limit direct sun exposure between 10 a.m. and 4 p.m., when UV radiation is at its strongest. Remember, however, that not all shade structures provide full sun protection. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Warning! Sand and water reflections boost the intensity of UV exposure.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the warmest months in Kailua?
What are the temperatures in Kailua in September?
What is the average humidity in September in Kailua?
How many days does it rain in September in Kailua?
What is the month with the warmest ocean in Kailua?
How warm is the water in September in Kailua?
What is the average length of the day in September in Kailua?
When is the sunrise / sunset in September in Kailua?
How long on average sun shines in September in Kailua?
What is the month with the highest UV index in Kailua?
What is the UV index intensity in September in Kailua?
Average temperature in September
Kailua, HI
- Average high temperature in September: 80.6°F
The warmest month (with the highest average high temperature) is September (80.6°F).
The month with the lowest average high temperature is February (74.5°F).
- Average low temperature in September: 77°F
The months with the highest average low temperature are September and October (77°F).
The coldest month (with the lowest average low temperature) is February (70.5°F).
Average pressure in September
Kailua, 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
Kailua, HI
- Average wind speed in September: 11.9mph
The windiest month (with the highest average wind speed) is July (14.1mph).
The calmest month (with the lowest average wind speed) is January (10.7mph).
Average humidity in September
Kailua, HI
- Average humidity in September: 75%
The months with the highest relative humidity are April, June, July, August and December (76%).
The months with the lowest relative humidity are January and November (74%).
Average rainfall in September
Kailua, HI
- Average rainfall in September: 0.94"
The wettest month (with the highest rainfall) is March (1.69").
The driest month (with the least rainfall) is July (0.55").
Average rainfall days in September
Kailua, HI
- Average rainfall days in September: 13 days
The month with the highest number of rainy days is March (16.9 days).
The month with the least rainy days is June (11.3 days).
Average sea temperature in September
Kailua, HI
- Average sea temperature in September: 80.4°F
The best month for swimming (with the highest average sea temperature) is September (80.4°F).
The coldest month (with the lowest average sea temperature) is March (75.7°F).
Average daylight in September /
Average sunshine in September
Kailua, 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: 9h and 2min
The month with the most sunshine is June (Average sunshine: 11h and 12min).
The month with the least sunshine is December (Average sunshine: 6h and 36min).
Average sunshine days in September
Kailua, HI
- Average sunshine days in September: 11 days
The month with the most sunshine days is June (13.6 days).
The months with the least sunshine days are March and November (6.6 days).
Average UV index in September
Kailua, HI
- Average UV index in September: 7
The months with the highest UV index are July, August, September and October (UV index 7).
The months with the lowest UV index are January, February, March, April, May, June, November and December (UV index 6).
Average cloud cover in September
Kailua, HI
- Average cloud cover in September: 27
The month with the most cloud cover is March (Cloud cover 36).
The month with the least cloud cover is September (Cloud cover 27).
Average visibility in September
Kailua, 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).
Kailua, Hawaii, USA
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