76% of flights from Phoenix to Ontario arrived on time over the past 12 months. That is about the typical U.S. route. The 7 a.m. departures ran on time 95% of the time; the 7 p.m. ones 58%. Most reliable airline: American Airlines (80%). 7% 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 PHX → ONT: when a flight was late, it was under 45 minutes late 58% of the time. About 1 in 15 flights landed an hour or more late, and 1 in 151 three hours or more; 0.5% were cancelled outright.
- On time or early76%
- 15–30 min late8.8%
- 30–60 min late7.4%
- 1–2 hours late5.1%
- 2–3 hours late1.0%
- 3+ hours late0.7%
- Diverted0.0%
- Cancelled0.5%
Share of all 3,012 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 |
|---|---|---|---|---|---|---|---|
| Southwest Airlines | 1,616 | 74% | 0.3% | −1 min | 6.6% | +49 min | Southwest Airlines |
| American Airlines | 1,396 | 80% | 0.9% | −7 min | 6.9% | +66 min | American Airlines 93%, SkyWest 3%, Envoy 3% |
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 PHX). Delays build through the day as late planes knock on, so early flights usually do best.
By airline and hour
| Departs | Southwest Airlines | American Airlines |
|---|---|---|
| 8 a.m. | 91% | 92% |
| 9 a.m. | 92% | — |
| 10 a.m. | — | 83% |
| 11 a.m. | — | 78% |
| noon | 79% | — |
| 3 p.m. | 73% | 81% |
| 5 p.m. | — | 74% |
| 6 p.m. | — | 71% |
| 7 p.m. | 58% | — |
| 8 p.m. | 54% | 74% |
| 9 p.m. | 55% | — |
Last flight of the day
On PHX → ONT, each airline's last flight of the day was cancelled 0.7% of the time, against 0.5% for its earlier flights (1.4× as often). It arrived 3+ hours late 0.5% of the time (earlier flights: 0.7%). 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 |
|---|---|---|---|---|---|
| American Airlines | 8:30 p.m. | 0.8% | 0.5% | 0.9% | first flight 10:45 a.m. |
| Southwest Airlines | 9:50 p.m. | 0.5% | 0.5% | 0.2% | first flight 8:05 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.
If you need to be in ONT tonight, book an earlier flight so there's a backup if it's cancelled.
By month
Each calendar month pooled over 2023–2026. Best: February (86%). Worst: May (73%).
By day of week
| Day | Flights | On time | Cancelled |
|---|---|---|---|
| Monday | 471 | 76% | 0.4% |
| Tuesday | 421 | 82% | 0.5% |
| Wednesday | 420 | 77% | 0.2% |
| Thursday | 457 | 78% | 0.0% |
| Friday | 459 | 72% | 1.1% |
| Saturday | 338 | 78% | 0.6% |
| Sunday | 446 | 73% | 0.9% |
Why flights were late
Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.
Cancellations: weather 6 · air traffic/airport 6 · airline 4
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 |
|---|---|---|---|---|---|---|
| AA 1666 | 6:03 p.m. | 237 | 73% | 1.3% | −6 min | American Airlines |
| AA 1238 | 8:43 p.m. | 129 | 71% | 0.0% | +3 min | American Airlines |
Worst days in the past year
| Date | Flights | On time | Cancelled |
|---|---|---|---|
| Dec 29, 2025 | 10 | 20% | 0 |
| Jun 13, 2026 | 5 | 20% | 1 |
| Nov 8, 2025 | 8 | 25% | 0 |
| Sep 26, 2025 | 8 | 25% | 2 |
| Jun 14, 2026 | 7 | 29% | 0 |
Nearby airport alternatives
Other ways to make the same trip, using airports within 60 miles of Phoenix or Ontario. PHX → LAX has been 5 points more reliable.
| Route | Flights | On time | Cancelled |
|---|---|---|---|
| PHX → ONT (this route) | 3,012 | 76% | 0.5% |
| PHX → LAX Phoenix Sky Harbor to Los Angeles LAX | 7,586 | 82% | 0.7% |
| PHX → SNA Phoenix Sky Harbor to Orange County John Wayne | 4,643 | 79% | 0.4% |
| PHX → BUR Phoenix Sky Harbor to Hollywood Burbank | 3,147 | 79% | 0.7% |
| PHX → LGB Phoenix Sky Harbor to Long Beach | 1,516 | 79% | 0.5% |
Questions
How often are flights from PHX to ONT on time?
76% of 3,012 scheduled flights from Phoenix, AZ to Ontario, CA arrived within 15 minutes of schedule between September 2025 and August 2026. 0.5% were cancelled.
What is the best time of day to fly PHX to ONT?
Flights scheduled to leave at 7 a.m. were the most reliable (95% on time). The 7 p.m. departures were the least (58%).
Which airline is most on time from PHX to ONT?
American Airlines: 80% of its 1,396 flights on the route arrived on time. Southwest Airlines: 74%.
What month has the most delays from PHX to ONT?
May (73% on time). The best month is February (86%), over 2023–2026.
Is the last flight of the day from PHX to ONT more likely to be cancelled?
Yes. Each airline's last PHX–ONT flight of the day was cancelled 0.7% of the time over the past year, against 0.5% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.
Related
- ONT → PHX (return)
- Phoenix Sky Harbor (PHX) delays by hour
- Flights into Ontario (ONT)
- Southwest Airlines on-time record
- American 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.