Route profile
ONT→PHX
Flight reliability, delays and best times to fly from Ontario to Phoenix, 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 87% of comparable major US routes (4,598 compared)
Calculated from 9,706 flights. How this is calculated
ONT → PHX arrives on time 85.1% of the time; the return trip, PHX → ONT, arrives on time 79.9% of the time, a 5.2-point gap between the two directions of the same city pair.
ONT → PHX spends 21.1 minutes on the ground on a 325-mile trip: 13.7 minutes from pushback to wheels-up at ONT and 7.4 minutes from touchdown to gate at PHX.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
This route holds up about the same all year, a steadier seasonal pattern than 96% of 3,357 comparable routes.
89.6% on time in its best month (February) against 80.2% in its worst (June).
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 3,357 in the comparison.
What sets this route apart
Where ONT to PHX differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
ONT to PHX is at its best against routes of similar length for flights scheduled at 9 PM: 78.7% arrive on time, 8.2 points ahead of the 70.5% those routes manage at that hour. Against all other routes the gap is 9.2 points.
ONT to PHX holds up on Sundays better than routes of similar length do: 83.1% on time to their 76.5%, a 6.6 points lead. Against all other routes the gap is 8.3 points.
July is kinder to ONT to PHX than to routes of similar length: 80.7% on time against 73.2%, 7.5 points better. Against all other routes the gap is 11 points.
American Airlines does better on ONT to PHX than on its routes of similar length: 85.5% on time here, 76.4% there, 9.1 points apart. Against all other routes the gap is 10.4 points.
ONT to PHX against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 9 PM departures | 78.7% | routes of similar length | 70.5% | +8.2 pts | 150 here, 35,903 there |
| Weekday: Sunday | 83.1% | routes of similar length | 76.5% | +6.6 pts | 1,365 here, 161,145 there |
| Month: July | 80.7% | routes of similar length | 73.2% | +7.5 pts | 998 here, 121,567 there |
| Airline: American Airlines | 85.5% | routes of similar length | 76.4% | +9.1 pts | 3,468 here, 154,104 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.
Why ONT → PHX flights are cancelled
July 2023 – July 2026
ONT → PHX cancelled 51 of 9,706 scheduled flights — about 1 in every 190. The reason filed most often was extreme weather, 49.0% of the cancellations coded on this route — about 1 in every 388 scheduled flights.
Share of cancellations
Of 51 cancelled departures carrying a reason code.
What each reason means
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
25 cancellations, 49.0% of the total.
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
19 cancellations, 37.3% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
7 cancellations, 13.7% of the total.
A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.
0 cancellations, 0.0% of the total.
Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.
51 coded cancellations were recorded on ONT → PHX; the section appears from 50.
When it goes wrong
July 2023 – July 2026
28 min late
against a median of 7 min early
Percentiles over 9,706 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at PHX after arriving from ONT.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 30% | High risk |
| 45 min | 14% | Some risk |
| 60 min | 9.3% | Some risk |
| 90 min | 4.5% | Low risk |
| 120 min | 2.8% | 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 0.53% of the time and diverts 0.04% of the time, which a late arrival never shows up in.
Chance of missing is the share of 9,651 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 28 minutes late (90th-percentile gate arrival delay), over 9,706 operations.
Any other layover length: connection checker.
Best time to fly
ONT → PHX flights departing 5–9 AM arrived on time 92.7% of the time, against 75.6% for 9 PM–5 AM departures, a gap of 17.1 percentage points.
By departure window
By departure hour
- 12 AM to 4 AM: too few flights to score
- 5 AM: 97.0% on time from 835 flights
- 6 AM: 90.6% on time from 1,320 flights
- 7 AM: too few flights to score
- 8 AM: 91.2% on time from 367 flights
- 9 AM: 93.1% on time from 758 flights
- 10 AM: 89.6% on time from 620 flights
- 11 AM: 90.2% on time from 225 flights
- 12 PM: 86.7% on time from 1,087 flights
- 1 PM: 84.9% on time from 409 flights
- 2 PM: 83.5% on time from 316 flights
- 3 PM: 75.2% on time from 391 flights
- 4 PM: 78.2% on time from 946 flights
- 5 PM: 75.7% on time from 500 flights
- 6 PM: 74.6% on time from 268 flights
- 7 PM: 77.1% on time from 1,053 flights
- 8 PM: 74.2% on time from 241 flights
- 9 PM: 78.7% on time from 151 flights
- 10 PM to 11 PM: too few flights to score
Why ONT → PHX 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 ONT → PHX. Only delays of 15 minutes or more are attributed.
Late-arriving aircraft is the largest cause on ONT → PHX, at 52.2%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 92.7% of the time and 9 PM–5 AM departures 75.6%.
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 | 5,038 | 84.5% | 0.50% | -6 min | 3.4% |
| American Airlines | 3,488 | 85.5% | 0.52% | -8 min | 5.9% |
| SkyWest Airlines | 717 | 87.3% | 0.14% | -8 min | 4.8% |
| Envoy Air | 247 | 92.3% | 0.00% | -11 min | 2.4% |
| Frontier Airlines | 216 | 75.0% | 3.24% | -6 min | 11.1% |
Southwest Airlines flew 51.9% of the 9,706 flights listed. Frontier Airlines cancelled 3.24% of its flights here against 0.00% for Envoy Air.
Envoy Air arrived on time 17.3 percentage points more often than Frontier Airlines on this route.
Other ways to fly Los Angeles to Phoenix
Airport pairs in the same two city markets, as the DOT defines them.
ONT → PHX is the most reliable pairing for this journey at 85.1% on time, against 83.2% for SNA → PHX.
Flying to PHX from the Los Angeles area? Compare ONT, LAX, SNA, BUR for PHX, with the same test for what counts as a real difference.
Weekly and seasonal patterns
By day of week
Saturday is historically the most reliable day and Friday the least, a gap of 5.8 percentage points.
By month
- Jan: 86.2%
- Feb: 89.6%
- Mar: 84.4%
- Apr: 86.5%
- May: 84.2%
- Jun: 80.2%
- Jul: 80.7%
- Aug: 85.6%
- Sep: 87.2%
- Oct: 85.6%
- Nov: 85.4%
- Dec: 86.7%
June is historically the weakest month and February the strongest, a spread of 9.4 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 84.4% from 225 flights
- August 2023: 83.0% from 239 flights
- September 2023: 87.6% from 217 flights
- October 2023: 89.6% from 260 flights
- November 2023: 92.4% from 263 flights
- December 2023: 89.3% from 271 flights
- January 2024: 84.5% from 254 flights
- February 2024: 88.0% from 242 flights
- March 2024: 82.7% from 279 flights
- April 2024: 84.8% from 277 flights
- May 2024: 76.8% from 297 flights
- June 2024: 81.1% from 276 flights
- July 2024: 78.1% from 289 flights
- August 2024: 88.9% from 290 flights
- September 2024: 88.2% from 262 flights
- October 2024: 90.0% from 292 flights
- November 2024: 90.1% from 273 flights
- December 2024: 90.8% from 282 flights
- January 2025: 88.8% from 254 flights
- February 2025: 93.3% from 240 flights
- March 2025: 85.2% from 291 flights
- April 2025: 87.8% from 289 flights
- May 2025: 88.4% from 294 flights
- June 2025: 80.8% from 260 flights
- July 2025: 82.0% from 263 flights
- August 2025: 84.0% from 237 flights
- September 2025: 85.6% from 227 flights
- October 2025: 76.7% from 258 flights
- November 2025: 73.6% from 272 flights
- December 2025: 80.1% from 282 flights
- January 2026: 85.3% from 261 flights
- February 2026: 87.5% from 240 flights
- March 2026: 85.4% from 289 flights
- April 2026: 86.9% from 252 flights
- May 2026: 87.8% from 254 flights
- June 2026: 78.3% from 224 flights
- July 2026: 78.7% from 231 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 82.5% against 87.9% in the 12 months before — declining by 5.4 percentage points.
Data and methodology
Calculated by FlyerIntel from 9,706 ONT → PHX 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