Guam weather in August
August is one of the least pleasant months in Guam: highs of 29°C (84°F) and about 315 mm (12.4 in) of rain on average. Nights average 28°C (82°F) and cloud cover 86% (NASA POWER, 2001–2025 averages). The sea averages 30°C (86°F). It is the wettest month of the year and the 5th warmest. Compared with July, it is about as warm and wetter; September brings highs of 29°C (84°F) and 278 mm (10.9 in) of rain.
Is August a good time to visit Guam?
least pleasant month Weather score 33/100.
August is one of the least pleasant months for weather in Guam. For better conditions, consider Dec–Jun.
Does it rain a lot in Guam in August?
Yes, it is one of the rainy months: about 315 mm (12.4 in) falls in an average August. It is the wettest month of the year.
How warm is Guam in August?
Days average 29°C (84°F) and nights 28°C (82°F).
Guam weather by month
| Month | High | Low | Rain | Cloud | Sea | Weather |
|---|---|---|---|---|---|---|
| January | 28°C (82°F) | 27°C (81°F) | 82 mm | 64% | 29°C (84°F) | best |
| February | 28°C (82°F) | 27°C (80°F) | 51 mm | 61% | 28°C (83°F) | best |
| March | 28°C (82°F) | 27°C (80°F) | 42 mm | 57% | 28°C (83°F) | best |
| April | 28°C (83°F) | 27°C (81°F) | 47 mm | 49% | 29°C (83°F) | best |
| May | 29°C (84°F) | 28°C (82°F) | 62 mm | 52% | 29°C (85°F) | best |
| June | 29°C (84°F) | 28°C (83°F) | 97 mm | 56% | 30°C (86°F) | best |
| July | 29°C (84°F) | 28°C (83°F) | 197 mm | 77% | 30°C (86°F) | fair |
| August | 29°C (84°F) | 28°C (82°F) | 315 mm | 86% | 30°C (86°F) | least pleasant |
| September | 29°C (84°F) | 28°C (82°F) | 278 mm | 85% | 30°C (86°F) | least pleasant |
| October | 29°C (84°F) | 28°C (83°F) | 231 mm | 73% | 30°C (86°F) | least pleasant |
| November | 29°C (84°F) | 28°C (83°F) | 136 mm | 55% | 29°C (85°F) | fair |
| December | 29°C (83°F) | 28°C (82°F) | 69 mm | 55% | 29°C (84°F) | best |
Sources: 2001–2025 monthly averages from NASA POWER (MERRA-2 reanalysis), sea temperature from Open-Meteo Marine. Page updated . How we rate months