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
The arrival of September brings an average high-temperature of a still warm 75.2°F (24°C), nearly identical to August's 75.4°F (24.1°C). September nighttime temperatures hover close to the daytime peak with an average of 70°F (21.1°C).Humidity
The average relative humidity in September is 79%.Rainfall
In Hakalau, in September, it is raining for 19.2 days, with typically 1.81" (46mm) of accumulated precipitation. In Hakalau, during the entire year, the rain falls for 227.7 days and collects up to 27.83" (707mm) of precipitation.Daylight
In September, the average length of the day is 12h and 14min.On the first day of September, sunrise is at 6:05 am and sunset at 6:35 pm. On the last day of the month, sunrise is at 6:11 am and sunset at 6:09 pm HST.
Sunshine
The average sunshine in September is 8.8h.UV index
The months with the highest UV index are May through December, with an average maximum UV index of 6. A UV Index value of 6 to 7 symbolizes a high threat to health from unsafe exposure to UV radiation for the average person.Note: A typical high UV index of 6 in September suggests the following recommendations:
Act on precautions and pay attention to sun safety recommendations. Avoidance of sunburn is obligatory. Limit direct sun exposure and seek shade between 10 a.m. and 4 p.m., the time of the most intense UV radiation, noting that shade structures may not provide total sun protection. Opt for tightly woven and loose clothing to enhance protection from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the average humidity in September?
How many days does it rain in September in Hakalau?
How many hours of daylight does Hakalau have in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Hakalau have in September?
What is the month with the highest UV index?
How high is the UV index in September?
Average temperature in September
Hakalau, 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
Hakalau, 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
Hakalau, 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
Hakalau, 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
Hakalau, 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
Hakalau, 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
Hakalau, 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
Hakalau, 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
Hakalau, 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
Hakalau, 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
Hakalau, 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).
Hakalau, Hawaii, USA
Weather forecast for your location
2. Allow the app to use your location