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 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's onset records a minor alteration in the average high-temperature to a still moderately hot 75.2°F (24°C) from August's 75.4°F (24.1°C). Keaau experiences an average nighttime temperature of 70°F (21.1°C) in September, reflecting a minor difference from the day's peak.Humidity
In Keaau, the average relative humidity in September is 79%.Rainfall
In Keaau, in September, it is raining for 19.2 days, with typically 1.81" (46mm) of accumulated precipitation. In Keaau, during the entire year, the rain falls for 227.7 days and collects up to 27.83" (707mm) of precipitation.Daylight
The average length of the day in September is 12h and 14min.On the first day of September, sunrise is at 6:04 am and sunset at 6:34 pm. On the last day of the month, sunrise is at 6:10 am and sunset at 6:08 pm HST.
Sunshine
The average sunshine in September in Keaau is 8.8h.UV index
May through December, with an average maximum UV index of 6, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high health vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: The daily high UV index of 6 during September translates into the following recommendations:
Implement precautions and maintain sun safety methods. Avoidance of sunburn is demanded. Stay in the shade and limit direct Sun exposure from 10 a.m. to 4 p.m., a time when UV radiation is particularly strong. Remember, however, that shade structures may not provide complete protection. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September in Keaau?
What is the average humidity in September in Keaau?
How much does it rain in Keaau in September?
What is the average length of the day in September in Keaau?
When are sunrise and sunset in September in Keaau?
How many hours of sunshine does Keaau have in September?
What are the months with the highest UV index in Keaau?
How high is the UV index in September in Keaau?
Average temperature in September
Keaau, HI
- Average high temperature in September: 75.2°F
The warmest month (with the highest average high temperature) is August (75.4°F).
The month with the lowest average high temperature is March (69.6°F).
- Average low temperature in September: 70°F
The month with the highest average low temperature is September (70°F).
The coldest month (with the lowest average low temperature) is March (64°F).
Average pressure in September
Keaau, HI
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is April (30.05"Hg).
The months with the lowest atmospheric pressure are September and October (29.97"Hg).
Average wind speed in September
Keaau, HI
- Average wind speed in September: 7mph
The windiest month (with the highest average wind speed) is August (7.6mph).
The calmest month (with the lowest average wind speed) is October (6.7mph).
Average humidity in September
Keaau, HI
- Average humidity in September: 79%
The month with the highest relative humidity is March (80%).
The months with the lowest relative humidity are January, May, June and July (78%).
Average rainfall in September
Keaau, HI
- Average rainfall in September: 1.81"
The wettest month (with the highest rainfall) is February (3.78").
The driest month (with the least rainfall) is June (1.1").
Average rainfall days in September
Keaau, HI
- Average rainfall days in September: 19.2 days
The month with the highest number of rainy days is March (22.9 days).
The month with the least rainy days is January (13.3 days).
Average daylight in September /
Average sunshine in September
Keaau, HI
- Average daylight in September: 12h and 1min
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 5min
The month with the most sunshine is June (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 6h and 30min).
Average sunshine days in September
Keaau, HI
- Average sunshine days in September: 2.5 days
The month with the most sunshine days is January (12.1 days).
The month with the least sunshine days is August (1.8 days).
Average UV index in September
Keaau, HI
- Average UV index in September: 6
The months with the highest UV index are May, June, July, August, September, October, November and December (UV index 6).
The months with the lowest UV index are January, February, March and April (UV index 5).
Average cloud cover in September
Keaau, HI
- Average cloud cover in September: 29
The month with the most cloud cover is March (Cloud cover 42).
The month with the least cloud cover is January (Cloud cover 26).
Average visibility in September
Keaau, 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).
Keaau, Hawaii, USA
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