September weather forecastPapaikou, HI
September
Weather in September
September, the first month of the autumn in Papaikou, is also a moderately hot month, with temperature in the range of an average high of 75.2°F (24°C) and an average low of 70°F (21.1°C).Temperature
The average high-temperature in September, at a still warm 75.2°F (24°C), reveals a modest deviation from August's 75.4°F (24.1°C). In Papaikou, September nights maintain a consistent temperature, with an average low of 70°F (21.1°C).Humidity
The average relative humidity in September is 79%.Rainfall
In September, the rain falls for 19.2 days. Throughout September, 1.81" (46mm) of precipitation is accumulated. Throughout the year, in Papaikou, there are 227.7 rainfall days, and 27.83" (707mm) of precipitation is accumulated.Ocean temperature
The month with the warmest seawater is September, with an average ocean temperature of 79.3°F (26.3°C).Note: For any water activity, the surface water temperatures in the range of 77°F (25°C) to 84.2°F (29°C) are deemed excellent and incredibly pleasant for longer durations.
Daylight
In September, the average length of the day is 12h and 14min.On the first day of the month, sunrise is at 6:05 am and sunset at 6:35 pm. On the last day of September, sunrise is at 6:11 am and sunset at 6:08 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 of 6 to 7 symbolizes a high health hazard from unsafe exposure to UV radiation for ordinary individuals.Note: In September, a regular UV index of 6 translates into these guidelines:
Prevent overexposure. Protection from the sun's harmful effects is needed. Avoid direct Sun exposure and stay in the shade between 10 a.m. and 4 p.m., a time when UV radiation is most intense, noting that not all shade structures offer full protection. Always opt for UVA and UVB-resistant sunglasses on radiant days. Stay vigilant! UV rays get a boost in intensity due to sand and water reflections.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Papaikou, 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
Papaikou, 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
Papaikou, 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
Papaikou, 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
Papaikou, 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
Papaikou, 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 sea temperature in September
Papaikou, HI
- Average sea temperature in September: 79.3°F
The best month for swimming (with the highest average sea temperature) is September (79.3°F).
The coldest month (with the lowest average sea temperature) is March (75.7°F).
Average daylight in September /
Average sunshine in September
Papaikou, HI
- Average daylight in September: 12h and 12min
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 48min
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
Papaikou, 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
Papaikou, 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
Papaikou, 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
Papaikou, 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).





