Guam Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Guam.
Climate overview of Guam
Guam, Micronesia, has a stable climate with little temperature variation across the year. Average daytime temperatures hover around 29°C (84°F), peaking in June at 30°C (86°F) and dipping in February to 28°C (82°F).
The city receives considerable rainfall, with around 2128 mm (84 in) annually. August is the wettest month. It has a distinct rainy season from July to November. May is the sunniest month, averaging 7.4 hours of sunshine per day.
Guam Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Guam - and find the best time to visit.
Monthly Temperature in Guam
With minimal seasonal shifts, Guam experiences a constant climate year-round. Typically, average maximum daytime temperatures range from a comfortable 30°C (86°F) in June to a comfortable 28°C (82°F) in the coolest month, February.
Nights vary from 27°C (81°F) in June to around 26°C (79°F) during the colder months.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Guam
Guam has a notably wet climate with abundant precipitation, recording 2128 mm (84 in) of rainfall per year. The climate in Guam shows significant variation throughout the year. Expect heavy rainfall in August, the wettest month, with an average of 362 mm (14 in) of precipitation over 20 rainy days.
In contrast, the driest month March offers drier and sunnier days, with around 59 mm (2.3 in) of rainfall over 20 rainy days. For more details, please visit our Guam Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in Guam
For those who appreciate different seasons, Guam serves as an ideal destination. Expect longer, more sun-filled days in May with an average of 7.4 hours of sunshine daily, and embrace the darker days in September, offering only 4.4 hours of daily sunlight.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Best Time to Visit Guam
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: January, February, March, April and May
- Warmest weather: all year round
- Most sunshine: March, April and May
- Wettest months: July, August, September, October and November, when rainfall is highest.
- Seasonal pattern: A distinct rainy season from July to November
Frequently asked questions about the climate in Guam
What is the best time to visit Guam?
January, February, March, April and May typically offer the most optimal weather in Guam. In contrast, July, August, September, October and November tend to have less optimal conditions. Guam has a distinct rainy season from July to November.
What temperatures can I expect in Guam?
Daytime highs range from 28°C (82°F) in February to 30°C (86°F) in June. Nighttime lows range from 26°C (79°F) to 27°C (81°F). Temperatures stay relatively stable year-round.
How much rain does Guam get?
Annual rainfall is around 2128 mm (84 in). August is the wettest month with 362 mm (14 in), while March is the driest with 59 mm (2.3 in).
How sunny is Guam?
Guam receives around 2,058 hours of sunshine per year. May is the sunniest month with 223 hours, while September is the cloudiest with just 133 hours. Overall, Guam enjoys abundant sunshine.
Guam 3-Day Forecast
Guam on the map
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