Cheap flights from St. Louis, MO to Ontario, CA
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Tips to know when travelling to Ontario
Cheapest one-way trip | $199 |
---|---|
Cheapest nonstop round-trip | $393 |
Cheapest round-trip | $427 |
Average round-trip | $595 |
Most popular airline | United Airlines |
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The most popular airlines for this route are United Airlines, and Alaska Airlines. St. Louis and Ontario have 40 direct flights per week.
Check-in for a flight from St. Louis to Ontario
Name | Carrier code | IATA Code | Passport needed during booking | Online check-in available |
---|---|---|---|---|
United Airlines | UAL | UA | Yes | No |
Alaska Airlines | ASA | AS | No | Opens 24 days before flight Closes 1 hours before flight |
Weather in Ontario
Average Weather
Month | Average monthly max temperature | Average monthly min temperature |
January | 18°C | 7°C |
February | 18°C | 7°C |
March | 20°C | 8°C |
April | 23°C | 10°C |
May | 25°C | 13°C |
June | 29°C | 16°C |
July | 33°C | 19°C |
August | 33°C | 20°C |
September | 32°C | 18°C |
October | 27°C | 15°C |
November | 22°C | 10°C |
December | 17°C | 7°C |
14 day forecast
Frequently asked questions
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