Guam weather by month
2006-2025, 20 years of records · Not a forecast
Guam is hot all year, and the seasons are defined by rainfall. Roughly January to May is the dry season, and July to November is the wet season and typhoon season. June and December are the transitions between them.
It is a short-stay resort destination, so one weather event can reshape a whole trip. In the wet season, watch for typhoon news; in the dry season, plan around sunscreen and the resort pool.
December to February gave the best mix of comfortable warmth and few rain days in Guam. To dodge the rain, February (13 rain days) was the stretch to look at, not September and October (24).
Each month in a line
| JanuaryGood | hot, rain on every second day | 30° / 24° |
|---|---|---|
| FebruaryGood | properly hot, frequent rain | 30° / 24° |
| March | hot, rain every other day | 31° / 24° |
| April | seriously hot, rain every other day | 31° / 25° |
| May | very hot, rain on every second day | 32° / 25° |
| June | seriously hot, rain on every second day | 31° / 25° |
| July | hot, rain nearly every day | 31° / 25° |
| August | properly hot, rain almost daily | 31° / 25° |
| September | hot, rain almost daily | 31° / 25° |
| October | hot, rain nearly every day | 31° / 25° |
| November | properly hot, rain almost daily | 31° / 25° |
| DecemberGood | hot, rain on every second day | 30° / 25° |
The 12 months in numbers
Temperatures hardly moved: 32°C in May against 30°C in January.
| Month | High | Low | Rain days | Rainfall | Humidity | Clear days | Sea |
|---|---|---|---|---|---|---|---|
| January | 30° | 24° | 18 days | 163mm | 80% | 5 days | 29° |
| February | 30° | 24° | 13 days | 100mm | 79% | 6 days | 28° |
| March | 31° | 24° | 15 days | 91mm | 80% | 8 days | 28° |
| April | 31° | 25° | 16 days | 104mm | 82% | 9 days | 29° |
| May | 32° | 25° | 17 days | 139mm | 82% | 7 days | 29° |
| June | 31° | 25° | 19 days | 155mm | 82% | 4 days | 30° |
| July | 31° | 25° | 22 days | 314mm | 83% | 1 day | 30° |
| August | 31° | 25° | 23 days | 451mm | 83% | 0 days | 30° |
| September | 31° | 25° | 24 days | 444mm | 84% | 0 days | 30° |
| October | 31° | 25° | 24 days | 427mm | 84% | 1 day | 30° |
| November | 31° | 25° | 20 days | 186mm | 83% | 9 days | 30° |
| December | 30° | 25° | 19 days | 121mm | 82% | 8 days | 29° |
Enter your dates to see how that stretch went in each of the past 20 years.
Common questions
When is the best time to visit Guam?
December to February gave the best mix of comfortable warmth and few rain days in Guam. To dodge the rain, February (13 rain days) was the stretch to look at, not September and October (24).
Which month is driest in Guam?
February. Over 2006-2025 it averaged 13 rain days and 100 mm of rain.
Which month is warmest in Guam?
May, with highs averaging 32°C and lows 25°C. Temperatures hardly moved: 32°C in May against 30°C in January.