September lies in the rainy season in Guam as the Pacific island frequently experiences cloudy skies and intense spells of rain. The average temperatures are between 76°F (24.4°C) and 87°F (30.6°C), with humid days and nights. The precipitation is characteristic of the tropics, with occasional heavy spells that push the monthly average to 14.2" (361mm). Rain jackets and umbrellas become necessary as brief showers lower the heat. September is the month with the least sunshine of 132 hours in the month. Southern Guam is home to cascading waterfalls that offer mesmerizing views in the wet season. Watch out for tropical storms in Guam when planning sea excursions. Wear water-proof shoes while venturing out on the trails. Summer clothing is usually sufficient during the day as well as night. There are plenty of indoor options suitable for all ages, even on rainy nights.