Route profile
PHX→ONT
Flight reliability, delays and best times to fly from Phoenix to Ontario, 325 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 75% of comparable major US routes (4,598 compared)
Calculated from 9,700 flights. How this is calculated · What counts as on time
PHX → ONT arrives on time 79.9% of the time; the return trip, ONT → PHX, arrives on time 85.1% of the time, a 5.2-point gap between the two directions of the same city pair.
PHX → ONT spends 19.6 minutes on the ground on a 325-mile trip: 14.3 minutes from pushback to wheels-up at PHX and 5.3 minutes from touchdown to gate at ONT.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What sets this route apart
Where PHX to ONT differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
PHX to ONT is at its best against routes of similar length for flights scheduled at 4 PM: 80.2% arrive on time, 6.5 points ahead of the 73.7% those routes manage at that hour. Against all other routes the gap is 9.5 points.
PHX to ONT struggles most at 10 PM: 63.2% of its flights scheduled then arrive on time, 5.8 points behind the 69.0% on routes of similar length at the same hour. Against all other routes the gap is 8.5 points.
In May, PHX to ONT runs 4.7 points below routes of similar length, 72.9% on time to 77.6%.
SkyWest Airlines does better on PHX to ONT than on its routes of similar length: 87.7% on time here, 81.6% there, 6.1 points apart. Against all other routes the gap is 6.4 points.
Southwest Airlines’ flights on PHX to ONT arrive on time 77.9% of the time, 3.2 points below the 81.1% it manages on its routes of similar length.
PHX to ONT against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 4 PM departures | 80.2% | routes of similar length | 73.7% | +6.5 pts | 393 here, 70,249 there |
| Hour: 10 PM departures | 63.2% | routes of similar length | 69.0% | −5.8 pts | 342 here, 28,347 there |
| Month: May | 72.9% | routes of similar length | 77.6% | −4.7 pts | 838 here, 94,437 there |
| Airline: SkyWest Airlines | 87.7% | routes of similar length | 81.6% | +6.1 pts | 716 here, 141,300 there |
| Airline: Southwest Airlines | 77.9% | routes of similar length | 81.1% | −3.2 pts | 5,012 here, 369,708 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 325 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
When it goes wrong
July 2023 – July 2026
38 min late
against a median of 5 min early
Percentiles over 9,700 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at ONT after arriving from PHX.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 36% | Likely to miss |
| 45 min | 20% | High risk |
| 60 min | 12% | Some risk |
| 90 min | 5.8% | Some risk |
| 120 min | 3.0% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 0.38% of the time and diverts 0.08% of the time, which a late arrival never shows up in.
Chance of missing is the share of 9,655 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 38 minutes late (90th-percentile gate arrival delay), over 9,700 operations.
Any other layover length: connection checker.
Best time to fly
PHX → ONT flights departing 5–9 AM arrived on time 92.8% of the time, against 67.2% for 9 PM–5 AM departures, a gap of 25.6 percentage points.
By departure window
By departure hour
- 12 AM to 5 AM: too few flights to score
- 6 AM: 95.4% on time from 131 flights
- 7 AM: 93.0% on time from 712 flights
- 8 AM: 92.2% on time from 717 flights
- 9 AM: 91.6% on time from 526 flights
- 10 AM: 84.2% on time from 867 flights
- 11 AM: 85.8% on time from 667 flights
- 12 PM: 83.4% on time from 278 flights
- 1 PM: 81.9% on time from 250 flights
- 2 PM: 80.5% on time from 669 flights
- 3 PM: 81.2% on time from 697 flights
- 4 PM: 80.2% on time from 395 flights
- 5 PM: 72.2% on time from 791 flights
- 6 PM: 72.4% on time from 637 flights
- 7 PM: 66.6% on time from 303 flights
- 8 PM: 71.0% on time from 971 flights
- 9 PM: 69.8% on time from 728 flights
- 10 PM: 63.2% on time from 343 flights
- 11 PM: too few flights to score
Why PHX → ONT runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for PHX → ONT. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on PHX → ONT, at 60.8%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 92.8% of the time and 9 PM–5 AM departures 67.2%.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| Southwest Airlines | 5,031 | 77.9% | 0.30% | -3 min | 5.4% |
| American Airlines | 3,488 | 80.2% | 0.49% | -6 min | 7.4% |
| SkyWest Airlines | 717 | 87.7% | 0.14% | -7 min | 3.8% |
| Envoy Air | 247 | 91.5% | 0.00% | -7 min | 2.0% |
| Frontier Airlines | 217 | 81.2% | 1.84% | -8 min | 6.6% |
Southwest Airlines flew 51.9% of the 9,700 flights listed. Frontier Airlines cancelled 1.84% of its flights here against 0.00% for Envoy Air.
Envoy Air arrived on time 13.6 percentage points more often than Southwest Airlines on this route.
Other ways to fly Phoenix to Los Angeles
Airport pairs in the same two city markets, as the DOT defines them.
PHX → LAX is the most reliable pairing for this journey at 83.0% on time, against 79.9% for PHX → ONT.
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Friday the least, a gap of 8.7 percentage points.
By month
- Jan: 83.5%
- Feb: 85.6%
- Mar: 80.5%
- Apr: 80.5%
- May: 72.9%
- Jun: 73.5%
- Jul: 74.4%
- Aug: 81.4%
- Sep: 79.3%
- Oct: 81.0%
- Nov: 84.6%
- Dec: 83.1%
May is historically the weakest month and February the strongest, a spread of 12.7 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 77.3% from 225 flights
- August 2023: 80.1% from 239 flights
- September 2023: 75.2% from 219 flights
- October 2023: 80.1% from 261 flights
- November 2023: 90.5% from 263 flights
- December 2023: 89.3% from 271 flights
- January 2024: 78.7% from 254 flights
- February 2024: 86.4% from 242 flights
- March 2024: 81.4% from 279 flights
- April 2024: 82.1% from 274 flights
- May 2024: 69.1% from 293 flights
- June 2024: 79.9% from 275 flights
- July 2024: 72.1% from 289 flights
- August 2024: 82.4% from 290 flights
- September 2024: 84.4% from 262 flights
- October 2024: 83.8% from 292 flights
- November 2024: 87.9% from 272 flights
- December 2024: 82.9% from 281 flights
- January 2025: 87.8% from 255 flights
- February 2025: 87.1% from 240 flights
- March 2025: 80.8% from 291 flights
- April 2025: 82.7% from 289 flights
- May 2025: 77.8% from 294 flights
- June 2025: 70.8% from 260 flights
- July 2025: 77.9% from 263 flights
- August 2025: 81.4% from 237 flights
- September 2025: 77.2% from 227 flights
- October 2025: 78.7% from 258 flights
- November 2025: 75.6% from 273 flights
- December 2025: 77.2% from 282 flights
- January 2026: 84.2% from 261 flights
- February 2026: 83.3% from 240 flights
- March 2026: 79.5% from 288 flights
- April 2026: 76.2% from 252 flights
- May 2026: 71.7% from 254 flights
- June 2026: 68.9% from 224 flights
- July 2026: 70.6% from 231 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 77.2% against 82.1% in the 12 months before — declining by 4.9 percentage points.
Data and methodology
Calculated by FlyerIntel from 9,700 PHX → ONT flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed