Season by season
Dry season (December–June)
Lower humidity and steady trade winds make this the most comfortable time to walk around the plaza and the memorials, and the water at Piti is usually at its clearest. Showers are short. It is also Guam’s busiest visitor season, so dolphin cruises and snorkelling tours fill up around New Year, Lunar New Year and Golden Week.
Wet season (July–November)
Hot and humid, with heavy downpours most likely in the afternoon and overnight. Sightsee in the morning, keep the museum for a wet hour, and expect the lawns at Asan to be soggy after rain. The night market carries on in all but the worst weather.
Sea conditions & typhoons
Piti and Asan lie on Guam’s sheltered western side, so the sea is often calm, but a distant storm can send swell onto the reef and cancel boat and snorkelling trips for a day or two. Typhoons are possible in any month and likeliest from about August to November; operators will cancel or reschedule when warnings are issued.
Month by month
| Month | Avg high | Avg low | Rainfall | Crowds |
|---|---|---|---|---|
| January | 30°C | 24°C | 130 mm | Busy |
| February | 30°C | 24°C | 110 mm | Busy |
| March | 30°C | 24°C | 70 mm | Quiet |
| April | 31°C | 25°C | 80 mm | Quiet |
| May | 31°C | 25°C | 110 mm | Quiet |
| June | 31°C | 25°C | 165 mm | Quiet |
| July | 31°C | 25°C | 300 mm | Busy |
| August | 31°C | 24°C | 410 mm | Busy |
| September | 31°C | 24°C | 360 mm | Quiet |
| October | 31°C | 24°C | 300 mm | Quiet |
| November | 31°C | 25°C | 210 mm | Quiet |
| December | 30°C | 24°C | 150 mm | Busy |
Temperatures and rainfall are approximate long-term averages; individual years vary, and a single typhoon can change a month completely.
Festivals & events
- March: Chamorro Month (Mes CHamoru) brings cultural displays, school performances and events around the island, including Guam History and Chamorro Heritage Day early in the month
- July: Liberation Day on 21 July, Guam’s biggest holiday, with a long parade along Marine Corps Drive through Hagåtña and memorial services at Asan and other wartime sites
- December: the procession of Santa Marian Kamalen on 8 December, when thousands follow the statue from the cathedral through the streets of the capital
- All year: the Wednesday night market at Chamorro Village, the capital’s weekly gathering
Our advice
For walking the town, January to April is the kindest stretch — drier, breezier and a little less humid. Whatever the month, see the outdoor sites before ten in the morning or after four in the afternoon, and book water activities for the morning. If you are on the island on 21 July, expect road closures around the parade route. Region-wide advice is on the when to go page.
