Best time to visit Guam: weather and seasons by month

Guam has two seasons, not four. The dry trade-wind season runs January to May: steady breezes, lower humidity and the most reliable beach and snorkelling days. The rainy season runs July to November, when showers are heavy, seas turn rough on exposed coasts, and the island sits in the zone where typhoons form.

The table below gives the verdict, crowd level and price band for each month, plus what actually changes your trip.

Temperatures barely move: expect 26–31 °C in every month, with the warmest and most humid stretch from May to September. What changes is rain, wind and sea state.

January to March is the driest and breeziest window, which is why it is also the most popular. April and May stay mostly dry but heat up, and May is the month when the island has historically seen early storms — Mawar arrived in May 2023, so check the forecast even in the dry season.

June is a transition month: showers become more frequent, humidity climbs, and hotel demand drops. July to October is the core of the rainy season, with August usually the wettest and the highest storm risk. November still carries late-season typhoon potential, though rain eases toward the end of the month. December brings the trade winds back and is a solid beach month, priced for the holidays.

Guam's demand is driven by short-haul Asian holidays more than by Western school breaks. Late December to early January, Lunar New Year (late January or February), Golden Week (late April to early May) and the Asian summer holidays in August are the peaks, with high prices and high demand in Tumon.

The cheapest window is September to November, when prices drop but you accept storm risk and rougher seas. March and April are the value picks inside the good-weather season: medium prices, medium crowds, dry days.

One local pattern worth knowing: village fiestas run on weekends all year, each village honouring its patron saint with Mass, a procession and open-house food. Visitors are often welcomed, but fiestas can close roads and fill local restaurants.

Liberation Day on 21 July brings a parade on Marine Corps Drive in Hagåtña plus road closures and a carnival for weeks around it — good if you want local colour, awkward if you planned to drive the island that day. All Souls' Day on 2 November and Santa Marian Kamalen on 8 December are public holidays with processions and office closures.

Holy Week and Good Friday fall in March or April depending on the year; expect processions and some closures. The Guam History and CHamoru Heritage Day holiday on the first Monday of March sits inside CHamoru Month, which brings cultural events and a fair — another reason March is the strongest pick.

Whatever month you choose, buy travel insurance that covers weather delays. Mawar showed that a serious storm can land outside the usual July–November window, and a cancelled flight or a closed hotel is the one thing that ruins a Guam trip.

If your priority is reliable beach weather, book March or April. If your priority is the lowest price, book September or October and keep a spare day in the plan for a washed-out excursion. If you are tied to school holidays, December is the best compromise between weather and cost.

Guam is small enough that a wet day rarely ruins a whole trip: build one flexible day into any rainy-season plan and you will not lose much.