January weather forecast
Guam, USA

January in Guam marks the beginning of the dry season, transitioning from the wetter end-of-year months. Temperatures during this month typically lie between 75°F (23.9°C) and 84°F (28.9°C). Compared to December, which experiences slightly more rainfall and marginally cooler temperatures, January offers a warmer and drier environment. While Guam, being a relatively small island, does not have notable weather variations between cities, the entire region enjoys the consistent climate.

Interestingly, January and February jointly claim the title of being the coldest months of the year for Guam. Yet, the term "cold" is relative as the temperatures are still quite pleasant by most standards. Rainfall is significantly reduced from the wetter months preceding it, making January one of the best months for outdoor activities and exploration.

The northeast trade winds persist during this time, moderating temperatures and keeping the conditions comfortable. These winds, blowing at speeds from 10mph (16.1km/h) to 20mph (32.2km/h), also play a role in reducing the chance of rain. Ocean temperatures, slightly cooler than the land, provide a refreshing contrast and are inviting for swimmers and divers. In comparison, February maintains a similar climate pattern, but with a tad lower temperatures, making January slightly warmer.

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• Hagåtña - January »
  The months with the highest humidity in Hagåtña are January, March through May, October through December, with an average relative humidity of 78%. The months with the highest humidity in Hagåtña are January, March through May, October through December, with an average relative humidity of 78%.
• Dededo - January »
  The months with the highest humidity in Dededo are January, March through May, October through December, with an average relative humidity of 78%. January through August, October through December, with an average maximum UV index of 7, are months with the highest UV index in Dededo.
• Santa Rita - January »
  January, March through May, October through December, with an average relative humidity of 78%, are most humid months in Santa Rita, Guam. The months with the highest humidity in Santa Rita are January, March through May, October through December, with an average relative humidity of 78%.
• Agat - January »
  January, March through May, October through December, with an average relative humidity of 78%, are most humid months in Agat, Guam. January, March through May, October through December, with an average relative humidity of 78%, are the most humid months in Agat.
• Piti - January »
  The months with the highest humidity in Piti are January, March through May, October through December, with an average relative humidity of 78%. January through August, October through December, with an average maximum UV index of 7, are months with the highest UV index in Piti.
• Talofofo - January »
  January through August, October through December, with an average maximum UV index of 7, are months with the highest UV index in Talofofo, Guam. January through August, October through December, with an average maximum UV index of 7, are months with the highest UV index in Talofofo.
• Inarajan - January »
  The months with the highest humidity in Inarajan are January, March through May, October through December, with an average relative humidity of 78%. January, March through May, October through December, with an average relative humidity of 78%, are the most humid months in Inarajan, Guam.
• Merizo - January »
  January in Merizo typically exhibits a tropical maritime climate, with constant high humidity and temperature. The months with the highest UV index in Merizo are January through August, October through December, with an average maximum UV index of 7.
• Umatac - January »
  January, March through May, October through December, with an average relative humidity of 78%, are most humid months in Umatac. January in Umatac, Guam, ushers in the new year accompanied by warm temperatures, slight humidity, and moderate rainfall.
• Guam National Wildlife Refuge - January »
  On the first day of January in Guam National Wildlife Refuge, sunrise is at 6:43 am and sunset at 6:03 pm. January in Guam National Wildlife Refuge reveals a transition out of the rainy season, with less precipitation and clearer skies than the preceding month.