The Climate of
Guam
Magellan Monument, Umatac
What is the climate of Guam like?
Guam is a territory of the United States situated at 13°N in the Western Pacific. It is the largest and most populous of the Mariana Islands, but a separate political entity from the Northern Mariana Islands. Guam is about 48 km (30 mi) long and from 6 to 12 km (4–7 mi) wide. The island is of volcanic origin; in the south, the terrain is mountainous, while the northern part is a plateau. The central part of the island (where the capital, Hagåtña, is located) is undulating country.
Guam has a typical tropical oceanic climate, with moderately high temperatures and humidity which vary little throughout the year. Average temperature is 27°C (81°F), and the daily range of temperature is quite small—about 4°C/10°F.
Rainfall is substantial, reaching an annual average of more than 2,000 millimeters (80 inches), with a wetter season from June to November. Guam has moderately large amounts of sunshine, averaging between six and eight hours a day, in spite of a large number of days on which some rain falls. Much of the rainfall is in the form of short, heavy showers but days with continuous rain are more frequent in the wetter months.
Although the combination of temperature and humidity is often rather muggy and oppressive, particularly at night, the daytime temperatures are usually moderate and feel more comfortable because of the brisk winds, both daytime sea breezes and the predominant and regular trade winds.
Guam lies in the typhoon belt of the Western Pacific and is occasionally subject to widespread storm damage. The main season for such storms is from July to November. The worst of these storms may only affect the island every two or three years, but the much larger area of heavy rain associated with a cyclone contributes to the heavier rainfall of these months.
| Climate data for Hagåtña | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Average high °C (°F) | 84.9 (29.4) | 84.9 (29.4) | 85.8 (29.9) | 87.3 (30.7) | 88.0 (31.1) | 88.0 (31.1) | 87.1 (30.6) | 86.5 (30.3) | 86.7 (30.4) | 86.7 (30.4) | 86.5 (30.3) | 85.6 (29.8) | 86.5 (30.3) |
| Daily mean °C (°F) | 80.2 (26.8) | 79.9 (26.6) | 80.8 (27.1) | 81.9 (27.7) | 82.6 (28.1) | 82.6 (28.1) | 81.9 (27.7) | 81.3 (27.4) | 81.3 (27.4) | 81.7 (27.6) | 81.9 (27.7) | 81.1 (27.3) | 81.4 (27.5) |
| Average low °C (°F) | 75.6 (24.2) | 75.0 (23.9) | 75.6 (24.2) | 76.5 (24.7) | 77.2 (25.1) | 77.4 (25.2) | 76.6 (24.8) | 76.3 (24.6) | 76.3 (24.6) | 76.5 (24.7) | 77.2 (25.1) | 76.8 (24.9) | 76.4 (24.7) |
| Average precipitation mm (inches) | 5.0 (126) | 4.5 (115) | 2.8 (70) | 3.6 (91) | 4.3 (109) | 7.1 (180) | 12.1 (308) | 17.2 (436) | 14.2 (360) | 11.8 (300) | 9.2 (233) | 6.0 (152) | 97.8 (2,480) |
| Source: www.pogodaiklimat.ru | |||||||||||||
References
- E. A. Pearce, Charles Gordon Smith, (1990) The Hutchinson World Weather Guide, John Murray Press. ISBN 1859863426
- Timothy L. Gall, (ed.), (2003), Worldmark Encyclopedia of the Nations, Eleventh Edition, Thomson Gale
- Hugh Chisholm, (ed.), (1911), Encyclopædia Britannica, Eleventh edition, Cambridge University Press
The Climate of
Guam
In summary:
Guam has a tropical climate with little seasonal variation in temperatures. Average temperature is 27°C (81°F). Rainfall is substantial, reaching an annual average of more than 200 cm (80 in), with a wetter season from June to November when tropical cyclones may occur.