Month by Month
January
Peak dry season, ideal beach weather
Dry season delivers calm seas and daytime highs around 86°F (30°C). Beach conditions stay consistent with minimal rain interruptions, though hotel rates peak and dive sites see more traffic from holidaymakers extending their New Year breaks.
February
Warm and dry, excellent conditions
Low humidity and steady sunshine make this the most comfortable month, with only 2-3 inches of rainfall. Water visibility reaches 100+ feet at offshore reefs, and crowds thin out after mid-month as prices drop slightly from January peaks.
March
Hot and dry, prime beach season
Temperatures climb toward 88°F (31°C) with strengthening sun that requires higher SPF and earlier beach sessions. Rain remains rare enough that outdoor plans rarely need backup options, though spring break brings weekend crowds to Tumon Bay.
April
Very hot, last of the dry season
Heat intensifies to 90°F (32°C) with rising humidity signaling the approaching wet season. Afternoon cloudbursts become possible after 3pm, but mornings stay dry for snorkeling and most rainfall evaporates within an hour.
May
Hot and increasingly humid
Humidity jumps noticeably and rain frequency doubles from April, though showers tend to be brief and warm. The Micronesia Island Fair draws regional visitors mid-month, creating busy periods at hotels near the festival grounds in Paseo Stadium.
June
Transition to wet season, occasional rain
Wet season begins with 8-10 inches of rain, mostly arriving as afternoon downpours that cool things down for an hour then pass. Ocean swells increase enough to create shore break at some beaches, and dive operators occasionally cancel trips on windier days.
July
Rainy season begins, warm showers
Rainfall hits 10+ inches with daily showers likely, though Liberation Day festivities on July 21 proceed rain or shine. Warmer water temperatures (84°F/29°C) attract more marine life to reefs, but afternoon storms regularly disrupt outdoor plans after 2pm.
August
Heavy rainfall, typhoon risk
Heavy rainfall peaks at 12-14 inches and typhoon watches become routine, with storm tracks monitored throughout the month. When typhoons stay distant, diving conditions can be excellent between systems, but you need flexible plans and trip insurance.
September
Peak typhoon season, frequent storms
Typhoon season reaches its statistical peak with the highest likelihood of direct hits that can shut down the island for 2-3 days. Between storms, high humidity and frequent squalls make outdoor activities challenging, and many visitors postpone trips entirely.
October
Wet and stormy, typhoon season continues
Storm risk continues though slightly reduced from September, with 11-13 inches of rain and persistent cloud cover. The BBQ Block Party offers a cultural reason to visit despite weather uncertainty, but beach days remain unreliable.
November
Rainfall decreasing, improving conditions
Rainfall drops to 8-9 inches as typhoon season winds down, and dry spells between systems grow longer. Ocean conditions calm noticeably in the final two weeks, creating a shoulder season window with lower prices and improving weather.
December
Dry season returns, holiday crowds
Dry season returns with rainfall under 4 inches and steady sunshine rebuilding beach crowds. Holiday fiestas fill weekends with local celebrations, and room rates climb toward New Year as winter visitors from Japan and Korea arrive.
Beaches and Swimming
Gun Beach and Ritidian Point offer calmer water than the crowded Tumon strip, though you'll need a rental car to reach them. Visit before 10am from March through May when heat becomes oppressive and shade disappears by midday. Avoid August through October entirely unless you enjoy swimming in choppy water between typhoon systems, and skip the western beaches near Apra Harbor where ship traffic clouds the water.
Diving and Snorkeling
The SMS Cormoran and Tokai Maru wrecks sit in the same spot at 100 feet, creating a two-ship dive that takes 40 minutes from Apra Harbor. Book mornings in January or February when visibility tops 100 feet and currents stay manageable for drift diving along the reefs. Don't bother with Tumon Bay snorkeling where boat traffic stirs up sand—drive 20 minutes north to Pati Point instead where reef fish crowd the shallows. Water temperature holds at 82-84°F year-round, so a 3mm shorty handles the chill at depth.
Hiking and Nature
The Mount Lam Lam trail climbs 1,300 feet in two miles through sword grass that slices exposed skin, so wear long pants despite the heat. Hike between December and March when rain stays minimal and trails dry out enough to avoid the slick red mud that stains everything it touches. The Two Lovers Point overlook costs $3 and requires no effort, but the view is identical to what you get free from the cliffside parking area 100 feet south. Skip hiking entirely from July to October when downpours flood trails and leeches emerge in the wet jungle.
Cultural Festivals
Liberation Day on July 21 fills Hagåtña with a parade and carnival that runs regardless of rain, celebrating the 1944 U.S. recapture of the island from Japan. The Micronesia Island Fair in May brings dancers and food vendors from across the region to Paseo Stadium, with three-day passes running $15. Don't expect village fiestas to operate on published schedules—they start when the lechon (roast pig) finishes cooking, usually an hour past the stated time. December fiestas intensify around Christmas with nearly every village hosting an open celebration where you'll eat for free if you show up and chat with anyone's grandmother.
Budget Travel
Skip hotels entirely and book vacation rentals in Tamuning or Harmon where one-bedrooms rent for $70-90 per night, half the cost of Tumon beachfront properties. Eat lunch at King's Restaurant or Proa for $8-10 plates of red rice, kelaguen, and grilled meat instead of $20 resort burgers. Rental cars cost $35-50 daily and you'll need one since taxis charge $25+ for short trips and buses run infrequently. Avoid visiting during Liberation Day week in July or Christmas week when prices jump 30-40% despite being the wettest and most crowded times of year.
Festivals & Events
Guam Micronesia Island Fair
MayThree-day celebration showcasing Micronesian culture through traditional dance, crafts, and food from across the region. Best opportunity to experience authentic island traditions outside your resort.
Liberation Day
JulyGuam's biggest annual celebration commemorating freedom from World War II occupation, featuring a carnival, parade, and fireworks. Expect larger crowds and higher hotel rates around July 21st.
Guam BBQ Block Party
OctoberMonthly street festival featuring local barbecue, live music, and craft vendors in various village locations. Good way to sample Chamorro cooking and mingle with locals in a relaxed setting.
Christmas celebrations and fiestas
DecemberVillages across Guam host traditional fiestas with processions, feasts, and decorations blending Chamorro and Catholic traditions. The holiday atmosphere peaks in late December with widespread festivities.
