Guam Weather, climate and geography
Weather and climate
Best time to visit
Temperatures are pretty constant. Only on rare occasions does the temperature dip below 21.1°C (70°F) or above 32.2°C (90°F). Average humidity is 66% but easterly trade winds of 6.4k-19.3 kph (4-12 mph) offset the dampness. The wet season is July through November, with transitional months being June and December. The best time to visit is Jan-May, the dry season.
Casual, lightweight attire is recommended for most times, but a rain jacket and an umbrella is always useful, especially during the rainy season.
Shaped like a footprint, and surrounded by a coral shelf, Guam's northern end is a plateau of rolling hills and cliffs rising 152m (500ft) above sea level. The island narrows in the middle, and the expanding southern half undulates with mountains and valleys cut by streams and waterfalls. The most sheltered beaches are on the western coast.