Route Reliability
Ontario → San Francisco
ONT–SFO · 363 miles · Ontario International Airport to San Francisco International Airport
- 70%
- Arrive within 15 minutes
- 14 min
- Average arrival delay
- 0.9%
- Cancelled
- 1,274
- Flights in the data
Data through May 2026.
Who flies it best
Ranked by on-time arrivals. Historical results, not predictions.
- 1.United Airlines72%1,113 flights
- 2.Frontier Airlines51%161 flights
What the data says
The 6–9 AM departure wins.
ONT–SFO flights departing between 6–9 AM arrived on time 88% of the time, versus 45% between 9 AM–12 PM.
Mondays have been rough.
ONT–SFO flights arrived on time 80% of the time on Tuesdays and just 62% on Mondays. That gap is worth planning around.
United Airlines has a clear lead on this route.
United Airlines arrived on time 72% of the time on this route; Frontier Airlines managed 51%.
Recent months have been rougher.
ONT–SFO flights arrived on time 63% of the time over the last three months in the data, compared with 77% in the three months before that.
Best historical flights
Ranked by on-time arrivals, minimum 100 flights. Past performance, not a promise.
Top flights by on-time rate
More flights on this route
The breakdown
- Mon62%(204 flights)
- Tue80%(151 flights)
- Wed71%(151 flights)
- Thu67%(184 flights)
- Fri68%(206 flights)
- Sat79%(158 flights)
- Sun67%(209 flights)
- 6–9 AM88%(344 flights)
- 9 AM–12 PM45%(111 flights)
- 12–3 PM80%(341 flights)
- 6–9 PM53%(349 flights)
- 9 PM–12 AM59%(118 flights)
Jun 84% → May 44% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 84% | 103 |
| July 2025 | 75% | 104 |
| August 2025 | 72% | 108 |
| September 2025 | 66% | 108 |
| October 2025 | 58% | 114 |
| November 2025 | 76% | 103 |
| December 2025 | 76% | 102 |
| January 2026 | 83% | 92 |
| February 2026 | 72% | 79 |
| March 2026 | 91% | 101 |
| April 2026 | 54% | 124 |
| May 2026 | 44% | 125 |
Same trip, other airports
Keep nerding
Based on 1,274 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.