88% of flights from Salt Lake City to Ontario arrived on time over the past 12 months. That is better than the typical U.S. route. The 8 a.m. departures ran on time 95% of the time; the 11 a.m. ones 84%. 4% of flights arrived more than an hour late or not at all.
How late?
The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for SLC → ONT: when a flight was late, it was under 45 minutes late 57% of the time. About 1 in 30 flights landed an hour or more late, and 1 in 248 three hours or more; 0.9% were cancelled outright.
- On time or early88%
- 15–30 min late4.7%
- 30–60 min late2.9%
- 1–2 hours late2.1%
- 2–3 hours late0.9%
- 3+ hours late0.4%
- Diverted0.0%
- Cancelled0.9%
Share of all 1,239 scheduled flights, past 12 months, by arrival time against schedule.
By airline
| Airline | Flights | On time | Cancelled | Typical arrival | 1h+ late | Avg when late | Operated by |
|---|---|---|---|---|---|---|---|
| Delta Air Lines | 1,209 | 88% | 0.8% | −8 min | 3.3% | +61 min | Delta Air Lines 72%, SkyWest 28% |
| Frontier Airlines | 30 | — | — | — | — | — | Frontier Airlines |
Airline = the name on the ticket. Regional flights (e.g. "Delta Connection") count under the ticketing airline, and the operator is listed.
Best time of day to fly
On-time rate by scheduled departure hour (local time at SLC). Delays build through the day as late planes knock on, so early flights usually do best.
By airline and hour
| Departs | Delta Air Lines |
|---|---|
| 8 a.m. | 95% |
| 11 a.m. | 84% |
| 3 p.m. | 90% |
| 10 p.m. | 87% |
Last flight of the day
On SLC → ONT, each airline's last flight of the day was cancelled 0.5% of the time, against 0.9% for its earlier flights, so here the last flight is actually the safer one. It arrived 3+ hours late 0.5% of the time (earlier flights: 0.5%). It matters more than the numbers suggest. Miss an earlier flight and there's another one that evening; miss the last one and you're usually waiting until morning.
| Airline | Last departure | Last: cancelled | Last: 3h+ late | Earlier: cancelled | Next morning |
|---|---|---|---|---|---|
| Delta Air Lines | 10:59 p.m. | 0.5% | 0.5% | 0.9% | first flight 8:01 a.m. |
Last flight = the airline's last scheduled departure on this route that day, on days it flies the route at least twice; past 12 months. Times are typical scheduled times over the latest three months.
By month
Each calendar month pooled over 2023–2026. Best: October (92%). Worst: July (84%).
By day of week
| Day | Flights | On time | Cancelled |
|---|---|---|---|
| Monday | 188 | 85% | 1.6% |
| Tuesday | 178 | 92% | 0.6% |
| Wednesday | 175 | 91% | 0.0% |
| Thursday | 185 | 87% | 0.5% |
| Friday | 184 | 90% | 0.0% |
| Saturday | 146 | 82% | 1.4% |
| Sunday | 183 | 89% | 2.2% |
Why flights were late
Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.
Cancellations: airline 10 · air traffic/airport 1
Month by month
Flight numbers on this route
Regular flights with at least 120 scheduled trips in the past year. Sorted by departure time.
| Flight | Departs | Flights | On time | Cancelled | Typical arrival | Operated by |
|---|---|---|---|---|---|---|
| DL 1614 | 10:59 p.m. | 349 | 88% | 0.6% | −9 min | Delta Air Lines |
Worst days in the past year
| Date | Flights | On time | Cancelled |
|---|---|---|---|
| Feb 16, 2026 | 3 | 0% | 0 |
| Feb 18, 2026 | 3 | 0% | 0 |
| Jul 17, 2026 | 4 | 25% | 0 |
| Jul 18, 2026 | 3 | 33% | 0 |
| Jan 11, 2026 | 3 | 33% | 0 |
Nearby airport alternatives
Other ways to make the same trip, using airports within 60 miles of Salt Lake City or Ontario. None has been clearly more reliable than SLC → ONT.
| Route | Flights | On time | Cancelled |
|---|---|---|---|
| SLC → ONT (this route) | 1,239 | 88% | 0.9% |
| PVU → SNA Provo to Orange County John Wayne | 412 | 91% | 0.0% |
| SLC → BUR Salt Lake City to Hollywood Burbank | 1,457 | 87% | 0.4% |
| SLC → LGB Salt Lake City to Long Beach | 1,569 | 86% | 0.4% |
| SLC → LAX Salt Lake City to Los Angeles LAX | 4,196 | 85% | 0.5% |
| SLC → SNA Salt Lake City to Orange County John Wayne | 1,858 | 82% | 0.7% |
Questions
How often are flights from SLC to ONT on time?
88% of 1,239 scheduled flights from Salt Lake City, UT to Ontario, CA arrived within 15 minutes of schedule between September 2025 and August 2026. 0.9% were cancelled.
What is the best time of day to fly SLC to ONT?
Flights scheduled to leave at 8 a.m. were the most reliable (95% on time). The 11 a.m. departures were the least (84%).
What month has the most delays from SLC to ONT?
July (84% on time). The best month is October (92%), over 2023–2026.
Is the last flight of the day from SLC to ONT more likely to be cancelled?
No, the opposite. Each airline's last SLC–ONT flight of the day was cancelled 0.5% of the time over the past year, against 0.9% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.
Related
- ONT → SLC (return)
- Salt Lake City (SLC) delays by hour
- Flights into Ontario (ONT)
- Delta Air Lines on-time record
- Frontier Airlines on-time record
- Connecting off this flight? Check the risk
Domestic flights by the airlines that report to the U.S. DOT, plus their regional partners. "On time" means arriving less than 15 minutes after schedule; cancelled and diverted flights count as not on time. Past performance is a guide, not a forecast. Method.