September weather forecastCaptain Cook, HI
September
Weather in September
The first month of the autumn, September, is also an agreeable month in Captain Cook, Hawaii, with an average temperature fluctuating between 69.8°F (21°C) and 73°F (22.8°C).Temperature
Transitioning into September, Captain Cook records an average high-temperature of a still agreeable 73°F (22.8°C), almost identical to August's 73.2°F (22.9°C). The September nights show a slight decrease to a mean low-temperature of 69.8°F (21°C).Humidity
The months with the highest humidity are June through September, with an average relative humidity of 81%.Rainfall
The month with the most rainfall is September, when the rain falls for 21.5 days and typically aggregates up to 1.81" (46mm) of precipitation.Daylight
The average length of the day in September is 12h and 14min.On the first day of September, sunrise is at 6:08 am and sunset at 6:38 pm. On the last day of the month, sunrise is at 6:14 am and sunset at 6:12 pm HST.
Sunshine
In Captain Cook, the average sunshine in September is 8.7h.UV index
May through October, with an average maximum UV index of 6, are months with the highest UV index in Captain Cook. A UV Index reading of 6 to 7 represents a high health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: The daily maximum UV index of 6 in September interprets into the following advice:
Implement precautions and maintain sun safety methods. Avoidance of sunburn is demanded. From 10 a.m. to 4 p.m., when UV radiation is at its strongest, limit direct exposure to the Sun and note that shade structures may not provide full sun 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
Average temperature in September
Captain Cook, HI
- Average high temperature in September: 73°F
The warmest months (with the highest average high temperature) are August and October (73.2°F).
The month with the lowest average high temperature is February (68.9°F).
- Average low temperature in September: 69.8°F
The month with the highest average low temperature is October (70°F).
The coldest month (with the lowest average low temperature) is March (64.8°F).
Average pressure in September
Captain Cook, HI
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is April (30.04"Hg).
The months with the lowest atmospheric pressure are September and October (29.96"Hg).
Average wind speed in September
Captain Cook, HI
- Average wind speed in September: 6.2mph
The windiest month (with the highest average wind speed) is May (6.3mph).
The calmest month (with the lowest average wind speed) is December (5.3mph).
Average humidity in September
Captain Cook, HI
- Average humidity in September: 81%
The months with the highest relative humidity are June, July, August and September (81%).
The month with the lowest relative humidity is February (73%).
Average rainfall in September
Captain Cook, HI
- Average rainfall in September: 1.81"
The wettest month (with the highest rainfall) is September (1.81").
The driest month (with the least rainfall) is January (0.75").
Average rainfall days in September
Captain Cook, HI
- Average rainfall days in September: 21.5 days
The month with the highest number of rainy days is August (21.8 days).
The month with the least rainy days is January (10.8 days).
Average daylight in September /
Average sunshine in September
Captain Cook, 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 42min
The month with the most sunshine is May (Average sunshine: 10h and 42min).
The months with the least sunshine are November and December (Average sunshine: 7h and 18min).
Average sunshine days in September
Captain Cook, HI
- Average sunshine days in September: 3.5 days
The month with the most sunshine days is January (12.7 days).
The month with the least sunshine days is May (3.2 days).
Average UV index in September
Captain Cook, HI
- Average UV index in September: 6
The months with the highest UV index are May, June, July, August, September and October (UV index 6).
The months with the lowest UV index are January, February, March, April, November and December (UV index 5).
Average cloud cover in September
Captain Cook, HI
- Average cloud cover in September: 28
The month with the most cloud cover is June (Cloud cover 31).
The month with the least cloud cover is January (Cloud cover 15).
Average visibility in September
Captain Cook, 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).
