September weather forecast
Wainaku, HI

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Weather in September

September, the first month of the autumn in Wainaku, is also a moderately hot month, with an average temperature varying between 75.2°F (24°C) and 70°F (21.1°C).

Temperature

The beginning of September records an average high-temperature of a still warm 75.2°F (24°C), marking a negligible difference from August's 75.4°F (24.1°C). Nighttime temperature sees a small decrement from daytime highs, dipping to an average of 70°F (21.1°C) during September.

Humidity

In Wainaku, the average relative humidity in September is 79%.

Rainfall

In Wainaku, in September, it is raining for 19.2 days, with typically 1.81" (46mm) of accumulated precipitation. In Wainaku, during the entire year, the rain falls for 227.7 days and collects up to 27.83" (707mm) of precipitation.

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 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 6:08 pm HST.

Sunshine

In September, the average sunshine 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 vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.
Note: An average maximum UV index of 6 in September leads to these recommendations:
Deflect overexposure. Sun protection is a necessity. Make an effort to avoid direct sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation, and note that objects like parasols or canopies might not offer full sun protection. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration. Be attentive! The UV exposure is heightened with reflections from sand and water.
Updated: Aug 17, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average September temperature?

In Wainaku, 75.2°F (24°C) is the average high-temperature and 70°F (21.1°C) is the average low-temperature during September.

What is the average humidity in September?

In Wainaku, the average relative humidity in September is 79%.

How much does it rain in September?

In Wainaku, in September, it is raining for 19.2 days, with typically 1.81" (46mm) of accumulated precipitation.

What is the month with the warmest ocean?

With an average ocean temperature of 79.3°F (26.3°C), September is the month with the warmest seawater.

What is the ocean temperature in September?

In Wainaku, in September, the average water temperature is 79.3°F (26.3°C). For swimming, diving, and other water activities, temperatures between 77°F (25°C) and 84.2°F (29°C) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

How many hours of daylight does Wainaku have in September?

In September, the average day length is 12h and 14min.

When are sunrise and sunset in September?

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 6:08 pm HST.

How long on average sun shines in September?

The average sunshine duration in September is 8.8h.

What are the months with the highest UV index?

The months with the highest UV index are May through December, with an average maximum UV index of 6.

What is the UV index reading in September?

The average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high hazard to health from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Wainaku, HI

Average temperature in September - Wainaku, 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
Wainaku, HI

Average pressure in September - Wainaku, 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
Wainaku, HI

Average wind speed in September - Wainaku, 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
Wainaku, HI

Average humidity in September - Wainaku, 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
Wainaku, HI

Average rainfall in September - Wainaku, 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
Wainaku, HI

Average rainfall days in September - Wainaku, 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
Wainaku, HI

Average sea temperature in September - Wainaku, 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
Wainaku, HI

Average daylight in September / Average sunshine in September - Wainaku, 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
Wainaku, HI

Average sunshine days in September - Wainaku, 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
Wainaku, HI

Average UV index in September - Wainaku, 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
Wainaku, HI

Average cloud cover in September - Wainaku, 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
Wainaku, HI

Average visibility in September - Wainaku, 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).

Wainaku, Hawaii, USA

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