UA8278United Airlines · SFO → ONT
live · 33m ago
Route confirmed United Airlines

UA8278 San FranciscoSFO OntarioONT

UA8278 by United Airlines flies from San Francisco (SFO) to Ontario (ONT).

Right nowNext departure today Operates daily
19:03

scheduled from SFO

The route today

live boards
SFOSan FranciscoOn-time likelySFO delay board →
ONTOntarioOn-time likelyONT delay board →
SFO→ONTevery carrier, schedules and on-time historyRoute intelligence →

Weather lens

Delay & cancellation outlook for this flight

Measured, 90-day sample
45%Chance of 15+ min delay
0.5%Chance of cancellation
+9 minTypical airport delay in this weather

Conditions at SFO and ONT are near their clear-air norm right now, so this reflects the route's recent baseline rather than a weather penalty. These figures come from both airports' records under conditions like today's, over the last 90 days.

Pro Flight Search tracking, 90 days · the weather × delay correlation study → · live weather risk by airport →

Tomorrow at San Francisco

Forecast

Tue 10 Nov, local date

High22°Clikely 20°C to 24°C
Low13°Clikely 12°C to 15°C

Forecast: GateWeather · incl. data from ECMWF (CC BY 4.0, modified) · Expected values for tomorrow from a forecast model, kept apart from today's measured figures.

Tomorrow at Ontario

Forecast

Tue 10 Nov, local date

High29°Clikely 28°C to 30°C
Low15°Clikely 14°C to 16°C

Forecast: GateWeather · incl. data from ECMWF (CC BY 4.0, modified) · Expected values for tomorrow from a forecast model, kept apart from today's measured figures.

When it flies

scheduled departures
061422
M
T
W
T
F
S
S

Each mark is a scheduled departure at its origin-local time. Today is highlighted.

Other San Francisco to Ontario flights today

same route · United Airlines
UA1482departs 11:00
UA5592departs 14:00
UA5763departs 16:19
UA436departs 16:35
UA1780departs 18:50
UA8224departs 19:00

If UA8278 is cancelled, these are the other United Airlines nonstop flights from San Francisco to Ontario on the same day, with scheduled departure times in SFO local time. Most flights that show a delay still operate. Rebooking usually helps only when that delay is very large. Every airline on this route →

How UA8278 actually runs

Pro Flight Search has tracked every published board update for UA8278 across the SFO and ONT boards: schedule changes, gate pushes and actual clocks. Combined risk score: 33.0/100. Based on airport operations, weather, and cached board history at SFO and ONT.

The verdict above is that record speaking, so it reflects how UA8278 operates rather than what the timetable promises. Numbers refresh as new flights operate.

Planning around UA8278? Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure

Cite this data

Journalists, bloggers, and researchers may cite this page with attribution and a link to Pro Flight Search.

Suggested citation

Pro Flight Search: UA8278 San Francisco to Ontario on-time performance, measured from the SFO and ONT airport boards.

Canonical URL
https://proflightsearch.com/flight/UA8278
How we measure this →