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National Oceanic and Atmospheric Administration
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Climate

The weather on Guam is warm throughout the year.
The weather on Guam is warm throughout the year. The temperature rarely exceeds 90° F (32.2° C) during the day or falls below 70° F (21.1° C) at night.

The weather on Guam is warm throughout the year with less humidity from November through March. The mean annual air temperature at sea level is about 82° F (27.2° C) with monthly means ranging from 80° F (26.7° C) in January to a little over 82° F (28° C) in June. The temperature rarely exceeds 90° F (32.2° C) during the day or falls below 70° F (21.1° C) at night. Guam's climate is characterized by two distinct seasons: a dry season from January to May and a rainy season from July to November. The mean annual rainfall varies from about 80 (203cm) inches in the central and coastal lowlands to 110 inches (279 cm) on the uplands in southern Guam. However, a wide variation in rainfall can occur from year to year.

The easterly trade winds, usually between 10 and 15 miles per hour (mph), are dominant throughout the year. Winds exceed 24 mph only during major tropical storms. Small scale storms, or squalls, can occur at any time and with little notice. The likelihood of major tropical storms (typhoons) is greatest during July through September, but they can occur during any month of the year.

 

 

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