Guam weather in January 2026

Expect daytime maximum temperatures of 30°C in Guam in January and high heat and humidity based on long-term weather averages. There are 6 hours of sunshine per day on average with 23 days with some rainfall and typically 130 mm of rainfall in the month.

  • 30°C maximum daytime temperature in January in Guam (Agana)30
    30°C max day temperature
  • 6 hours of sunshine per day
  • 23 days with some rainfall in January in Guam (Agana)23
    23 days with some rainfall
  • 24°C minimum night-time temperature in January in Guam (Agana)24
    24°C min night temperature
  • 11 hours of daylight per day in January in Guam (Agana)11
    11 hours of daylight per day
  • High heat & humidity in January in Guam (Agana)H
    High heat & humidity
  • 130 mm monthly rainfall in January in Guam (Agana)130
    130 mm of monthly rainfall
  • UV (maximum) index 10 (Very High) in January in Guam (Agana)10
    10 (Very High) UV index
  • 28°C sea temperature in January in Guam (Agana)28
    28°C sea temperature

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The January weather guide for Guam, represented by Agana, (Agana) 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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How hot is it in Guam in January?

Daytime temperatures usually reach 30°C in Agana, Guam in January with high heat and humidity, falling to 24°C at night.

How sunny is it in Guam in January?

There are normally 6 hours of bright sunshine each day in Agana, Guam in January - that's 50% of daylight hours.

How warm is the sea around Guam in January?

The average sea temperature around Agana, Guam in January is 28°C.

Does it rain in Guam in January?

There are usually 23 days with some rain in Agana, Guam in January and the average monthly rainfall is 130mm.

What is the chance of a typhoon in Guam in January?

On average less than 1 day in January in Agana, Guam is likely to be affected by the passage of one or more tropical storms.

Guam January sunrise & sunset times

Browse the sunrise and sunset times for Guam in January 2026. Select a month to view Guam sunrise and sunset times for the next 12 months. The Guam sunrise and sunset times shown below are for Agana.

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Thursday, 1st January 2026 06:44 18:05
Friday, 16th January 2026 06:48 18:13
Saturday, 31st January 2026 06:48 18:21

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