September weather forecast
Guam, USA

September in Guam is emblematic of the late stages of the wet season. During this month, temperatures usually range from 82°F (27.8°C) to 89°F (31.7°C). The frequent downpours and high humidity levels still dominate, though the month serves as a gradual bridge to the eventual decline of the monsoon's intensity.

Every corner of Guam is influenced by September's pronounced rainfall. The landscapes, which have been consistently soaked throughout the past few months, maintain their lush and vibrant appearance. While the intensity of the rains remains high, September often begins to show subtle signs of a shift towards the concluding phase of the wet season.

Rain remains a staple of September, but its frequency and intensity can start to taper off slightly compared to the peak wet months of July and August. The dependable northeast trade winds, with velocities from 10mph (16.1km/h) to 20mph (32.2km/h), endure in their role, delivering periodic refreshing breaks from the prevailing moisture and warmth.

The ocean waters around Guam, while still warm, can exhibit increased choppiness due to the prolonged wet conditions and occasional storm activities. Such dynamics necessitate heightened awareness for those indulging in marine ventures. As September fades, October ushers in the waning moments of the wet season, with the climate starting to hint at the impending drier months.

---

• Hagåtña - September »
  The month with the most rainfall in Hagåtña is September, when the rain falls for 28.1 days and typically aggregates up to 10.28" (261mm) of precipitation. September delivers yet another month of moderate tropical weather marked by hot days and cool nights.
• Dededo - September »
  Transitioning from August to September, Dededo observes an average high-temperature of a still moderately hot 84.4°F (29.1°C), differing subtly from the previous month. On the first day of September in Dededo, sunrise is at 6:09 am and sunset at 6:32 pm.
• Santa Rita - September »
  The month with the most rainfall in Santa Rita is September, when the rain falls for 28.1 days and typically aggregates up to 10.28" (261mm) of precipitation. On the last day of September, in Santa Rita, sunrise is at 6:10 am and sunset at 6:12 pm ChST.
• Agat - September »
  The month with the most rainfall in Agat is September, when the rain falls for 28.1 days and typically aggregates up to 10.28" (261mm) of precipitation. In Agat in September, during 28.1 rainfall days, 10.28" (261mm) of precipitation is typically accumulated.
• Piti - September »
  On the first day of September in Piti sunrise is at 6:09 am and sunset at 6:33 pm. In September, in Piti the rain falls for 28.1 days.
• Talofofo - September »
  Steady UV levels and visibility indicate clear, sunny autumn days, making September a vital transition month for Talofofo's weather. In the transition from August to September, Talofofo reports an average high-temperature of a still moderately hot 84.4°F (29.1°C), indicating a close resemblance to the prior month.
• Inarajan - September »
  The month with the most rainfall in Inarajan is September, when the rain falls for 28.1 days and typically aggregates up to 10.28" (261mm) of precipitation. The month with the most rainfall in Inarajan is September, when the rain falls for 28.1 days and typically aggregates up to 10.28" (261mm) of precipitation.
• Merizo - September »
  Transitioning into September, Merizo experiences an average high-temperature of a still warm 84.4°F (29.1°C), marking a minor shift from the preceding month. September is the month with the most rainfall in Merizo, Guam.
• Umatac - September »
  The month with the most rainfall in Umatac is September, when the rain falls for 28.1 days and typically aggregates up to 10.28" (261mm) of precipitation. On the first day of September in Umatac, Guam, sunrise is at 6:09 am and sunset at 6:33 pm.
• Guam National Wildlife Refuge - September »
  When are sunrise and sunset in September in Guam National Wildlife Refuge? In Guam National Wildlife Refuge, in September, the average water temperature is 85.1°F (29.5°C).