Best Flights starting from $141
from$141economy
San Francisco (SFO)
Sun, May 3
One-way
Ontario (ONT)
—
from$196economy
San Francisco (SFO)
Sat, May 2
One-way
Ontario (ONT)
—
from$356economy
San Francisco (SFO)
Fri, May 1
One-way
Ontario (ONT)
—
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Other Options for This Route
Other Destinations
San Francisco (SFO) to Los Angeles (Any) in May from $28
From $28
San Francisco (SFO) to San Diego (SAN) in May from $28
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San Francisco (SFO) to Denver (Any) in May from $50
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San Francisco (SFO) to Phoenix (Any) in May from $56
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San Francisco (SFO) to San Diego (SAN) in May from $56
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San Francisco (SFO) to San Diego (Any) in May from $56
From $56
Flights from Other Cities
Denver (Any) to Ontario (ONT) in May from $40
From $40
Denver (Any) to Ontario (ONT) in May from $56
From $56
Las Vegas (LAS) to Ontario (ONT) in May from $56
From $56
Omaha (OMA) to Ontario (ONT) in May from $80
From $80
Cleveland (Any) to Ontario (ONT) in May from $86
From $86
Grand Rapids (GRR) to Ontario (ONT) in May from $86
From $86
✈️ Flight Guide: San Francisco (SFO) → Ontario (ONT)
Complete travel information for your May journey
May is a high-demand month for travel between San Francisco International Airport (SFO) and Ontario International Airport (ONT) because of spring vacations and Memorial Day. Expect an uptick in weekly frequencies in the two weeks surrounding Memorial Day; peak travel days are usually the Friday before and Monday after the holiday. For budget-conscious travelers, midweek departures (Tuesdays and Wednesdays) often yield lower fares, while Friday–Sunday trips can be 15–25% higher. Book 3–6 weeks in advance for the best balance of price and availability, use fare alerts, and consider early morning flights for lower rates and fewer delays. Nearby destinations accessible from SFO include San Jose, Oakland, Palo Alto, Napa, and Sacramento; from ONT you can quickly access Los Angeles, Anaheim, Riverside, San Bernardino, Long Beach, and Palm Springs — making SFO→ONT convenient for both business and leisure itineraries.
Departing from San Francisco (SFO) FAQs
In May, there are typically multiple daily options between San Francisco International Airport (SFO) and Ontario International Airport (ONT), including both nonstop and one-stop itineraries. Frequency increases around Memorial Day weekend, so expect more flights and occasional schedule adjustments; check airline timetables or Google Flights for up-to-date departures. For the best fares, book early and be flexible with departure days.
Nonstop flights between San Francisco International Airport (SFO) and Ontario International Airport (ONT) typically take about 1 hour 20 minutes to 1 hour 40 minutes airborne. Total door-to-door travel time will be longer when you add check-in, security, and ground transport; plan for at least 3–4 hours from city center to city center. Always verify the scheduled block time on your ticket as it may vary by carrier and routing.
San Francisco International Airport (SFO) can be busy in May due to spring travel and holiday weekends; arrive at least 90 minutes before domestic departures and 2 hours for busy periods. Use TSA PreCheck or CLEAR if available to speed through security, and check real-time security wait times on the SFO app to optimize your arrival. Consider using curbside check-in or mobile boarding passes to reduce time inside the terminal.
From San Francisco International Airport (SFO), you can reach terminals via BART (Bay Area Rapid Transit) to the airport, airport shuttles, taxis, rideshares (Uber/Lyft), and rental cars. For early morning or late-night departures to Ontario International Airport (ONT), consider pre-booking a rideshare or rental car; if you plan to park, compare daily vs. long-term parking rates at SFO to save on extended trips. Booking airport parking or shuttle services in advance often secures the best rate for May travel.
Yes—airlines often publish seasonal schedules and targeted promotions for May, especially around Memorial Day. Expect occasional extra flights or fare sales from carriers like Southwest Airlines, Alaska Airlines, United Airlines, and American Airlines operating the SFO–ONT market; subscribe to airline newsletters and set fare alerts on Google Flights or Skyscanner to catch May deals. Remember that the best promotional fares usually require flexibility with travel dates and advance booking.
San Francisco International Airport (SFO) serves the entire Bay Area; nearby major cities include San Jose, Oakland, Palo Alto, and Sacramento, as well as tourist destinations like Napa and Sonoma. Travelers often route from these cities to SFO for flights to Ontario International Airport (ONT) to access Southern California attractions, business centers, and theme parks. Use multi-city search options if you plan to combine Bay Area stops before flying to ONT.
May arrivals at Ontario International Airport (ONT) are shaped by warm weather and increased leisure travel to theme parks and coastal areas. Travelers landing from San Francisco International Airport (SFO) should be ready for Memorial Day weekend surges and reserve rentals or shared rides in advance. ONT is a practical gateway to Los Angeles, Anaheim (Disneyland/Convention Center), Riverside and the Inland Empire business hubs, as well as beach communities like Long Beach and vacation spots such as Palm Springs. For a smooth arrival, check transit schedules, book rental cars early, and use online parking deals to reduce costs.
Arriving at Ontario (ONT) FAQs
Ontario International Airport (ONT) offers multiple ground transport options including car rentals, rideshares (Uber/Lyft), taxis, and regional shuttle services. Public transit connections such as Omnitrans and Metrolink serve nearby cities—note that service frequencies may change for holiday weekends in May, so check schedules ahead of arrival. For excursions to Los Angeles, Anaheim, Riverside, or Palm Springs, renting a car is often the fastest and most flexible choice.
Baggage claim and arrivals processing at Ontario International Airport (ONT) usually take 15–45 minutes for domestic flights, depending on aircraft size and throughput; car rental counters are conveniently located on-site but can have longer waits during busy May weekends. To speed things up, consider online check-in for your airline and reserve your rental car in advance; premium or expedited baggage services can also help if time is critical. During major events in the Inland Empire, allow extra time for shuttle and rental queues.
Ontario International Airport (ONT) provides access to major Southern California destinations including Los Angeles, Anaheim (home to Disneyland Resort), Riverside, San Bernardino, Long Beach, and Palm Springs. May is ideal for theme park visits and outdoor activities — expect warm, sunny weather in these areas. Use ONT as a gateway to both Inland Empire business centers and Southern California leisure destinations.
In May, Memorial Day weekend and graduation season often increase passenger volumes at Ontario International Airport (ONT), so plan for longer lines at ground transportation and rental counters. Weather is typically warm and dry, so check car rental availability in advance and allow additional time for traffic if heading to beach areas or theme parks. For cheaper arrival pricing, arrive midweek and consider alternate nearby airports if you find lower fares.
As of May, most U.S. airports, including Ontario International Airport (ONT), follow current CDC and local public health guidance, which may include recommendations rather than mandates for masks or testing. Airlines and rental car companies may have their own policies, so verify requirements with your carrier before travel. Keep a digital and paper copy of vaccination or test records if your itinerary includes international connections.
To save on ground transport at Ontario International Airport (ONT), compare pre-booked off-site parking, use ride-sharing pooled options, or check for shuttle packages included with some rental providers. Booking rental cars and parking ahead of time often locks in lower rates during busy May weekends, and many airports offer online coupons for long-term parking. Consider public transit like Omnitrans for budget-friendly travel to nearby cities if your arrival time aligns with schedules.
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May Events & Festivals Near SFO and ONT
May brings numerous cultural and seasonal events that can affect travel between San Francisco International Airport (SFO) and Ontario International Airport (ONT). In the Bay Area, spring festivals, graduation weekends at major universities, and cultural celebrations increase airport traffic. In Southern California, May features Cinco de Mayo events, Memorial Day weekend activities, and numerous concerts and sports events in Los Angeles and Anaheim (including theme-park seasonal programming). If you’re flying SFO→ONT in May, book early for event weekends, check hotel availability in nearby cities (Los Angeles, Anaheim, Riverside, Palm Springs), and plan ground transport ahead of time to avoid delays during event hours.
Best Time to Fly SFO → ONT in May
For May travel between San Francisco International Airport (SFO) and Ontario International Airport (ONT), the best times to fly are midweek (Tuesday–Thursday) and early-morning departures, which generally have lower fares and fewer delays. Avoid flying on the Friday before Memorial Day and the Sunday after, as these days are peak for higher prices and heavier traffic. If you can be flexible by one or two days, you’ll often find savings and a more relaxed travel experience. CTA: Search midweek May dates now to compare fares and secure a lower-priced itinerary.
Direct vs Connecting Flights: SFO to ONT in May
Nonstop flights from San Francisco International Airport (SFO) to Ontario International Airport (ONT) are the fastest option, typically taking about 1 hour 20–40 minutes in the air. Connecting flights can be cheaper, especially if routed through hubs like Los Angeles (LAX), Phoenix (PHX), or Denver (DEN), but add hours of travel time and increase the risk of missed connections. In May, weigh the value of saving $30–100 against the extra travel time—choose nonstop for convenience and connections for potential savings or schedule needs. CTA: Compare nonstop and connecting options for your May dates to find the best balance of price and travel time.
Airline Comparison for SFO → ONT — May Options
Common carriers serving the San Francisco International Airport (SFO) to Ontario International Airport (ONT) market include Southwest Airlines, Alaska Airlines, United Airlines, and American Airlines. Southwest often offers two free checked bags and competitive May fares, making it a strong value choice for families. Alaska Airlines emphasizes comfort and reliable service from bay area airports, while United and American provide extensive connections through their respective hubs—useful if you have frequent flyer status or need connecting itineraries. Compare base fares, baggage fees, and change policies before booking; for many May travelers, Southwest’s no-fee checked bag policy can offset a slightly higher ticket price. CTA: Check carrier pages and set fare alerts to compare May flights, then book the airline that fits your priorities for price and convenience.
Seasonal Travel Tips for SFO to ONT — May
Pack layers for May travel: San Francisco International Airport (SFO) often has cool, breezy mornings while Ontario International Airport (ONT) and surrounding Inland Empire locales are warmer and sunnier. Expect heavier traffic and higher prices around Memorial Day—book flights, parking, and rental cars early. If you're driving between airports or city centers, allow extra time for congestion, especially on I-5 and I-15 corridors. Consider early-morning flights to avoid afternoon delays and check weather and traffic apps the night before departure. CTA: Prepare for May travel now by booking your flight from San Francisco International Airport (SFO) to Ontario International Airport (ONT) and reserving ground transport in advance.
SFO to ONT Flight Time & Schedules — May Expectations
Typical nonstop flights from San Francisco International Airport (SFO) to Ontario International Airport (ONT) have an airborne time of approximately 1 hour 20 minutes to 1 hour 40 minutes; scheduled block time often lists 1 hour 30 minutes. Daily frequency in May can vary from a few nonstop flights up to several options depending on carrier scheduling and holiday demand—expect more departures in the weeks around Memorial Day. Morning and late afternoon waves are common, with midweek flights often offering the most competitive fares. For the latest schedule, check airline timetables or the SFO and ONT flight status pages and set alerts for any schedule changes.
How to Find Cheap Flights SFO to ONT in May
Best practices to find cheap flights from San Francisco International Airport (SFO) to Ontario International Airport (ONT) in May include: 1) Book 3–6 weeks ahead for domestic May travel and earlier for Memorial Day weekend; 2) Be flexible with departure days — Tuesdays and Wednesdays often have the lowest fares; 3) Use fare comparison tools and set price alerts on Google Flights, Skyscanner, or Kayak to catch flash sales; 4) Consider nearby airports (San Jose, Oakland) for discounted itineraries; and 5) Compare carry-on-only fares vs. checked-baggage bundles to find the real lowest price. CTA: Set a price alert now for May travel from San Francisco International Airport (SFO) to Ontario International Airport (ONT) to catch deals before they disappear.