Seattle–Tacoma International Airport
Seattle, United StatesSEA / KSEA
International hub · 132 direct destinations · 3 runways · longest runway 11,900 ft
52 °F · CloudySource: METAR observation via the NOAA Aviation Weather Center
Route
Seattle → Ontario
SEA
SeattleSeattle–Tacoma International Airport
SeattleSeattle–Tacoma International AirportONTOntarioOntario International Airport
OntarioOntario International Airport- Distance
- 957 mi
- Estimated flight time
- ~2h 25m
Same local time in Seattle and Ontario.
Observed nonstop
How often does this route fly?
Frequency
Several times a day
On average around 6.5 flights a day, observed from October 2025 to September 2026.
- 6.5
- flights per day
- 8
- busiest month · May
- 5
- quietest month · Jan
- 2 hr 9 min
- measured flight time
- 12 / 12
- months seen
Through the year
Per day, month by month
- 5Jan2026
- 5Feb
- 6Mar
- 6Apr
- 8May
- 8Jun
- 8Jul
- 7Aug
- 7Sep
- 6Oct2025
- 7Nov
- 6Dec
Airlines
Who flies it
Alaska Airlinesall year
SkyWest Airlinesall year
Frontier Airlinessummer
Air Transport Internationalspring
Delta Air Linesnow and then
Through the day
Departure times
Local time in Seattle. Most departures between 20:00 and 23:00.
- 00:00
- 01:00
- 02:00
- 03:00
- 04:00
- 05:00
- 06:00
- 07:00
- 08:00
- 09:00
- 10:00
- 11:00
- 12:00
- 13:00
- 14:00
- 15:00
- 16:00
- 17:00
- 18:00
- 19:00
- 20:00
- 21:00
- 22:00
- 23:00
Through the week
By weekday
- 6.9Mon
- 6.5Tue
- 5.9Wed
- 6.2Thu
- 7Fri
- 6.2Sat
- 6.6Sun
Fleet
Aircraft observed
- Embraer 175E75L42%
- Boeing 737-900B73921%
- Boeing 737 MAX 9B39M18%
- Boeing 737-800B7388%
- Airbus A321neoA21N3%
All the numbers in a table
| Month | Per day | Seen | Airlines |
|---|---|---|---|
| January 2026 | 5 | 154 |
|
| February 2026 | 5 | 135 |
|
| March 2026 | 6 | 170 |
|
| April 2026 | 6 | 183 |
|
| May 2026 | 8 | 214 |
|
| June 2026 | 8 | 234 |
|
| July 2026 | 8 | 244 |
|
| August 2026 | 7 | 226 |
|
| September 2026 | 7 | 209 |
|
| October 2025 | 6 | 190 |
|
| November 2025 | 7 | 206 |
|
| December 2025 | 6 | 172 |
|
Airlines observed on this route
From observed callsign routes on SEA-ONT - not a booking guarantee.
About this route
- Domestic route: both airports are in the same country.
- The opposite direction has also been observed as a direct connection.
- Direct destinations observed from Seattle: 132.
- Direct destinations observed from Ontario: 63.
The airports on this route
Ontario International Airport
Ontario, United StatesONT / KONT
Major airport · 63 direct destinations · 2 runways · longest runway 12,198 ft
84 °F · ClearSource: METAR observation via the NOAA Aviation Weather Center
Alternative airports for this journey
Same journey, a different airport nearby - with an observed direct connection.
BFI ONTKing County International Airport - Boeing FieldSeattle is about 6 mi from Seattle.View route →SEA SBDSan Bernardino International AirportSan Bernardino is about 21 mi from Ontario.View route →SEA SNAJohn Wayne Orange County International AirportSanta Ana is about 30 mi from Ontario.View route →SEA LGBLong Beach International AirportLong Beach is about 35 mi from Ontario.View route →
About the route from Seattle to Ontario
The observed direct connection between Seattle–Tacoma International Airport (SEA) and Ontario International Airport (ONT) covers approximately 957 mi. The estimated flight time is around 2h 25m. Air Transport International, Alaska Airlines, Delta Air Lines, Frontier Airlines and SkyWest Airlines have been observed on this connection in the available route data.
Frequently asked questions about this route
- How far is Seattle from Ontario by air?
- The great-circle distance between Seattle–Tacoma International Airport and Ontario International Airport is approximately 957 mi.
- How long is the flight from Seattle to Ontario?
- Based on the distance, the estimated flight time is about 2h 25m. This is an estimate, not a schedule.
- Is there a direct connection from Seattle to Ontario?
- Yes, a direct connection between SEA and ONT has been observed in our route data.
- Which airlines have been observed on this route?
- In the available route data: Air Transport International, Alaska Airlines, Delta Air Lines, Frontier Airlines and SkyWest Airlines.
- How often is there a flight from Seattle to Ontario?
- On average around 6.5 flights a day, measured over twelve months (October 2025 to September 2026) in the flight archive, with 2,337 observed flights. Mainly Alaska Airlines, SkyWest Airlines, Frontier Airlines. That is an observation, not a timetable.
- What is the current time difference between Seattle and Ontario?
- Same local time in Seattle and Ontario.
Where this data comes from
The route data comes from the flight archive (ADS-B, adsb.lol): which connections actually flew over the last twelve full months and who flew them, combined with our own airport, runway, and airline datasets. It is reference data about observed routes - not a current timetable and no claim about bookability.
The frequency and aircraft on this page come from the flight archive (ADS-B, 12 months, October 2025 to September 2026), summarized per route per month. We do not see every flight, so it is a floor, not a count.
Route data updated on October 11, 2026.