September weather forecastPrinceville, HI
September
Weather in September
September weather highlights include recording the highest low-temperature mark with an average 75.9°F (24.4°C) at the lower end. This period transitions toward fall with slightly reduced temperature and daylight hours when compared to August. However, the landscape continues its vibrant display, maintained by regular rainfall and high humidity. Despite being the gateway to autumn, the weather conditions upholds the tropical allure. Frequented by steadier winds, this time period often presents idyllic conditions for wind-based water sports.Temperature
Princeville's temperatures tend to reach their peak averages in September, with a high of 79.7°F (26.5°C) and a low of 75.9°F (24.4°C).Humidity
In Princeville, the average relative humidity in September is 76%.Rainfall
In Princeville, in September, it is raining for 18.7 days, with typically 1.54" (39mm) of accumulated precipitation. Throughout the year, there are 218.4 rainfall days, and 22.13" (562mm) of precipitation is accumulated.Daylight
In September, the average length of the day is 12h and 16min.On the first day of September, sunrise is at 6:21 am and sunset at 6:54 pm. On the last day of the month, sunrise is at 6:29 am and sunset at 6:25 pm HST.
Sunshine
The average sunshine in September is 8.7h.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 ordinary individuals.Note: A daily high UV index of 7 in September leads to these guidelines:
Implement precautions and maintain sun safety methods. Avoidance of sunburn is demanded. Stay out of direct sunlight between 10 a.m. and 4 p.m., when UV radiation is most intense, and remember that not all shade structures provide complete protection. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Princeville, HI
- Average high temperature in September: 79.7°F
The warmest month (with the highest average high temperature) is September (79.7°F).
The months with the lowest average high temperature are February and March (73.2°F).
- Average low temperature in September: 75.9°F
The month with the highest average low temperature is September (75.9°F).
The coldest month (with the lowest average low temperature) is February (68.5°F).
Average pressure in September
Princeville, HI
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is April (30.07"Hg).
The months with the lowest atmospheric pressure are September and October (29.98"Hg).
Average wind speed in September
Princeville, HI
- Average wind speed in September: 11.1mph
The windiest month (with the highest average wind speed) is July (12.3mph).
The calmest month (with the lowest average wind speed) is January (10mph).
Average humidity in September
Princeville, HI
- Average humidity in September: 76%
The months with the highest relative humidity are June, July, August, October and December (77%).
The month with the lowest relative humidity is January (75%).
Average rainfall in September
Princeville, HI
- Average rainfall in September: 1.54"
The wettest month (with the highest rainfall) is March (2.52").
The driest month (with the least rainfall) is April (1.3").
Average rainfall days in September
Princeville, HI
- Average rainfall days in September: 18.7 days
The month with the highest number of rainy days is August (21.1 days).
The month with the least rainy days is January (12.5 days).
Average daylight in September /
Average sunshine in September
Princeville, HI
- Average daylight in September: 12h and 18min
The month with the longest days is June (Average daylight: 13h and 30min).
The month with the shortest days is December (Average daylight: 10h and 48min).
- Average sunshine in September: 8h and 42min
The month with the most sunshine is June (Average sunshine: 9h and 42min).
The month with the least sunshine is November (Average sunshine: 6h and 12min).
Average sunshine days in September
Princeville, HI
- Average sunshine days in September: 5.3 days
The month with the most sunshine days is January (12.8 days).
The month with the least sunshine days is August (2.9 days).
Average UV index in September
Princeville, 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
Princeville, HI
- Average cloud cover in September: 38
The month with the most cloud cover is March (Cloud cover 47).
The months with the least cloud cover are January and September (Cloud cover 38).
Average visibility in September
Princeville, 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).
