Kailua, Oahu weather in September 2025

Expect 30°C daytime maximum temperatures in the shade with on average 9 hours of sunshine per day in Kailua, Oahu in September. Check more long-term weather averages for Kailua, Oahu in September before you book your next holiday to Hawaii in 2025/2026.

  • 30°C maximum daytime temperature in September in Kailua, Oahu30
    30°C max day temperature
  • 9 hours of sunshine per day
  • 8 days with some rainfall in September in Kailua, Oahu8
    8 days with some rainfall
  • 22°C minimum night-time temperature in September in Kailua, Oahu22
    22°C min night temperature
  • 12 hours of daylight per day in September in Kailua, Oahu12
    12 hours of daylight per day
  • High heat & humidity in September in Kailua, OahuH
    High heat & humidity
  • 44 mm monthly rainfall in September in Kailua, Oahu44
    44 mm of monthly rainfall
  • UV (maximum) index 11 (Extreme) in September in Kailua, Oahu11
    11 (Extreme) UV index
  • 27°C sea temperature in September in Kailua, Oahu27
    27°C sea temperature

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Kailua, Oahu by month

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The September weather guide for Hawaii (Kailua, Oahu) shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

Metric (°C / mm)  |  Imperial (°F / inches)

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More about the USA

How hot is it in Kailua, Oahu in September?

Daytime temperatures usually reach 30°C in Kailua, Oahu in September with high heat and humidity, falling to 22°C at night.

How sunny is it in Kailua, Oahu in September?

There are normally 9 hours of bright sunshine each day in Kailua, Oahu in September - that's 74% of daylight hours.

How warm is the sea around Kailua, Oahu in September?

The average sea temperature around Kailua, Oahu in September is 27°C.

Does it rain in Kailua, Oahu in September?

There are usually 8 days with some rain in Kailua, Oahu in September and the average monthly rainfall is 44mm.

Kailua, Oahu September sunrise & sunset times

Browse the sunrise and sunset times for Kailua, Oahu in September 2025. Select a month to view Kailua, Oahu sunrise and sunset times for the next 12 months.

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Monday, 1st September 2025 06:15 18:47
Monday, 15th September 2025 06:18 18:33
Tuesday, 30th September 2025 06:22 18:19

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