ON TIMEBOARD

F9 2678 on time

Frontier Airlines 2678: San Francisco to Ontario at 9:33 a.m. (past 12 months)

On time
58%
211 flights · likely 52–65%
Cancelled
2.4%
of scheduled flights
Typical arrival
+5 min
median vs schedule
When late
+77 min
average delay
Similar flights
75%
F9, same route & hour

About 1 in 2 F9 2678 flights from San Francisco arrived 15+ minutes late, diverted or cancelled over the past year (42%); 2.4% were cancelled. The typical flight landed 5 minutes late.

F9 2678: SFO → ONT

Scheduled to leave San Francisco at 9:33 a.m. local time. Over the past year it arrived on time 58% of the time (211 flights), worse than other F9 flights on the route at that hour (75%). Last seen in the data Aug 31, 2026.

Month by month

30%65%100%Aug 2025: 50% on time (16 flights)50AugSep 2025: 35% on time (17 flights)35SepOct 2025: 39% on time (18 flights)39OctNov 2025: 43% on time (21 flights)43NovDec 2025: 53% on time (15 flights)53DecJan 2026: too few flights (7 flights)JanMar 2026: too few flights (8 flights)MarApr 2026: too few flights (13 flights)AprMay 2026: 60% on time (20 flights)60MayJun 2026: 60% on time (30 flights)60JunJul 2026: 52% on time (31 flights)52JulAug 2026: 77% on time (31 flights)77Aug

By day of week

DayFlightsOn time
Monday4363%
Tuesday15—
Wednesday15—
Thursday3858%
Friday4264%
Saturday17—
Sunday4156%

Why it was late

Late inbound plane 78%Airline (crew, maintenance, ops) 19%Air traffic & airport (NAS) 3%

All flights SFO → ONT · Connecting off F9 2678? Check the risk

Questions

How often is F9 2678 from SFO to ONT late?

Frontier Airlines 2678 from San Francisco, CA to Ontario, CA arrived 15 or more minutes late, was diverted or was cancelled on 42% of 211 scheduled flights between September 2025 and August 2026. 2.4% were cancelled.

Flight numbers change. Figures cover flights with this airline, number and route only. "Likely range" is the 95% interval for the true on-time rate given the number of flights. This is history, not live status: check Frontier Airlines for today's flight. Method.