The Guam climate is easily described as tropical, with sun and a bit of rain year round. Being a tropical island Guam climate has a lot of humidity in the air. Throughout the day, the temperatures on the island can range between lows 70s to the high 80’s, but sometimes can reach into the 90’s on a really hot day.
Even though Guam climate is pretty constant, we actually do have two two seasons, the rainy season which is from the month of July to December, and the dry season which is from the month of January to June. And we do have a storm here and there. Between the 2 seasons, there is not too much change in temperature, but the humidity makes the rainy season a bit hotter.
The dry season is a bit breezy and coincides with the trade winds season, during the dry season months, rain is not common, but an occasional storm or two can bring some rain showers. During the dry season, the air is less humid and rains less, which can sometimes can cause brush fires in the mountains. During the rainy season, the air is more humid, and flooding in low lying areas do sometimes occur.
Though there are two seasons, you can still expect the sun to shine at any time of the day. Usually rain clouds intensify for only a short period and then move on, leaving the sun to dry up the roads. It is not uncommon for rain clouds to form over a perfect sunny day as well.
Typhoons on Guam are also common. Though for the past couple of years, the island has not experienced any typhoons, but we did have a few close encounters with minor tropical storms, which brought high winds and rain but nothing damaging. The island does very well in preparing for typhoons, with weather officials usually giving a 2-3 day warning before the storm makes land contact. Most homes are typhoon resistant constructed out of concrete and equipped with typhoon shutters.
Just keep in mind, climate on Guam is full of surprises. It could be sunny and warm one minute, and the next thing you know it’s pouring rain for a good 10 minutes and back to nice sunny weather. The weather gives the island a tropical feel once you get used to it. If there is one thing for sure, you definitely do not need is your winter wardrobe.