✈️ Flight Guide: Ontario (ONT) → Tamuning (GUM)

There are typically no nonstop commercial flights from Ontario International Airport (ONT) to Antonio B. Won Pat International Airport (GUM); most itineraries in September route through major hubs like Los Angeles (LAX), Honolulu (HNL), Tokyo (NRT/HND) or Manila (MNL). Airlines you can expect on ONT→GUM itineraries include United (connecting via LAX), Hawaiian Airlines (via HNL), Philippine Airlines (via MNL), and Japan Airlines/ANA if routed through Japan. Check schedules and book early for September travel to secure the best connections and prices.

Total travel time from Ontario International Airport (ONT) to Antonio B. Won Pat International Airport (GUM) varies based on routing and layovers; typical itineraries in September range from about 11 to 18+ hours door-to-door. Flights routed via Los Angeles and a single overnight transpacific segment (e.g., LAX→GUM) average 12–14 hours total, while connections through Asia (Tokyo or Manila) may extend total elapsed time depending on layover length.

September often falls in Guam's shoulder season (after summer and during typhoon season), which can bring lower airfares from Ontario International Airport (ONT). Expect periodic sales and lower demand midweek; however, prices fluctuate with carrier promotions and routing. Search 6–10 weeks ahead and set price alerts to capture discounted ONT to GUM flights in September.

Ontario International Airport (ONT) is accessible by rideshare (Uber/Lyft), taxis, private shuttles, and regional bus services. In September, allow extra time for Labor Day holiday weekends or local events; parking on-site includes short-term and long-term lots with shuttle services to terminals. If you’re coming from nearby cities like Los Angeles, Anaheim, Riverside or San Bernardino, plan for typical Southern California traffic and arrive 2–3 hours before international departures.

U.S. citizens traveling from Ontario International Airport (ONT) to Antonio B. Won Pat International Airport (GUM) (a U.S. territory) generally need a valid government-issued photo ID such as a state ID or U.S. passport. In September, ensure your ID complies with TSA REAL ID regulations if using a state ID for airport security. International visitors to Guam should verify visa and passport requirements with their embassy before booking.

September is often less busy at Ontario International Airport (ONT) than peak summer months, but you may see spikes around Labor Day weekend. Airlines sometimes adjust frequencies seasonally, so some direct regional connections may be reduced; it’s wise to confirm your ONT flight schedule close to travel dates and allow extra time for security and check-in.

When arriving at Antonio B. Won Pat International Airport (GUM) in September, expect tropical warmth and higher humidity, with seasonal showers possible due to the Western Pacific typhoon season. The airport is compact and efficient; after arrival you’ll clear customs (if applicable), collect baggage and find taxis, rental cars, and shuttle services to Tumon, Hagatna (Hagåtña), Tamuning, Dededo and other Guam destinations. Have local contact details and hotel reservations ready for faster transfers.

September is within Guam's typhoon season, so travelers arriving at Antonio B. Won Pat International Airport (GUM) should monitor weather forecasts and airline alerts. While many flights operate normally, severe weather can cause delays or cancellations; buy refundable or changeable fares for September travel and enroll in airline notifications for real-time updates.

From Antonio B. Won Pat International Airport (GUM) you can choose taxi services, hotel shuttles, rental cars, and local buses to reach Tumon (the main resort district), Hagatna (the capital) and surrounding towns like Tamuning and Dededo. In September, some shuttle services may operate on adjusted schedules during storms, so confirm pickup times with your hotel and consider pre-booking transfers for reliability.

From Antonio B. Won Pat International Airport (GUM) you can access top Guam destinations including the resort area of Tumon, the historic sites of Hagatna (Hagåtña), scenic beaches in Ypao and Ritidian, and nearby islands such as Saipan and Tinian via regional flights. September offers fewer crowds and lower hotel rates, though water activities may be affected by weather — check local operators for availability.

Antonio B. Won Pat International Airport (GUM) offers a selection of shops, restaurants and passenger services; lounge access depends on airline partners or pay-per-use lounges. In September some retail hours may adjust during low-season weekdays or weather events, but core services remain available. Check the airport's official site or your carrier for up-to-date facility hours before travel.

In September, standard airport health measures typically include routine sanitation and passenger screening; specific requirements can change, so verify carrier and Guam government health advisories prior to travel. Pack any necessary medications, have electronic boarding passes ready, and carry documentation if special medical declarations are required. Consider travel insurance for unexpected medical or weather-related disruptions.