Route profile
ONT→SLC
Flight reliability, delays and best times to fly from Ontario to Salt Lake City, 558 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 93% of comparable major US routes (4,598 compared)
Calculated from 3,726 flights. How this is calculated
ONT → SLC arrives on time 91.8% of the time; the return trip, SLC → ONT, arrives on time 88.9% of the time, a 3.0-point gap between the two directions of the same city pair.
ONT → SLC spends 21.7 minutes on the ground on a 558-mile trip: 14.4 minutes from pushback to wheels-up at ONT and 7.3 minutes from touchdown to gate at SLC.
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 99% of 3,357 comparable routes.
95.4% on time in its best month (November) against 87.9% in its worst (January).
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 SLC differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
ONT to SLC is at its best against routes of similar length for flights scheduled at 4 PM: 92.9% arrive on time, 22.1 points ahead of the 70.8% those routes manage at that hour. Against all other routes the gap is 22.2 points.
ONT to SLC holds up on Fridays better than routes of similar length do: 92.4% on time to their 76.8%, a 15.6 points lead. Against all other routes the gap is 16.2 points.
July is kinder to ONT to SLC than to routes of similar length: 91.5% on time against 70.1%, 21.4 points better. Against all other routes the gap is 21.8 points.
Delta Air Lines does better on ONT to SLC than on its routes of similar length: 92.3% on time here, 81.8% there, 10.5 points apart. Against all other routes the gap is 10.8 points.
ONT to SLC against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 4 PM departures | 92.9% | routes of similar length | 70.8% | +22.1 pts | 197 here, 100,978 there |
| Weekday: Friday | 92.4% | routes of similar length | 76.8% | +15.6 pts | 542 here, 273,729 there |
| Month: July | 91.5% | routes of similar length | 70.1% | +21.4 pts | 436 here, 202,580 there |
| Airline: Delta Air Lines | 92.3% | routes of similar length | 81.8% | +10.5 pts | 2,389 here, 409,288 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 558 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
10 min late
against a median of 13 min early
Percentiles over 3,726 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SLC after arriving from ONT.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 16% | High risk |
| 45 min | 7.9% | Some risk |
| 60 min | 5.5% | Some risk |
| 90 min | 3.2% | Low risk |
| 120 min | 2.1% | 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 1.05% of the time and diverts 0.03% of the time, which a late arrival never shows up in.
Chance of missing is the share of 3,686 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 10 minutes late (90th-percentile gate arrival delay), over 3,726 operations.
Any other layover length: connection checker.
Best time to fly
ONT → SLC flights departing 9 AM–12 PM arrived on time 96.5% of the time, against 89.6% for 12–3 PM departures, a gap of 6.9 percentage points.
By departure window
By departure hour
- 12 AM to 4 AM: too few flights to score
- 5 AM: 93.5% on time from 201 flights
- 6 AM: 94.8% on time from 929 flights
- 7 AM to 8 AM: too few flights to score
- 9 AM: 97.4% on time from 192 flights
- 10 AM to 12 PM: too few flights to score
- 1 PM: 89.4% on time from 1,127 flights
- 2 PM to 3 PM: too few flights to score
- 4 PM: 92.9% on time from 198 flights
- 5 PM: 92.0% on time from 891 flights
- 6 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why ONT → SLC runs late
July 2023 – July 2026
crew, maintenance, boarding and fueling, all within the carrier’s control
the inbound aircraft was late, so this flight started late
weather severe enough to stop this flight specifically
airspace and airport capacity, including weather-driven flow control
Share of the delay minutes US DOT attributed to each cause for ONT → SLC. Only delays of 15 minutes or more are attributed.
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 |
|---|---|---|---|---|---|
| Delta Air Lines | 2,419 | 92.3% | 1.20% | -14 min | 3.3% |
| SkyWest Airlines | 1,121 | 93.0% | 0.09% | -11 min | 2.4% |
Delta Air Lines flew 68.3% of the 3,540 flights listed. Delta Air Lines cancelled 1.20% of its flights here against 0.09% for SkyWest Airlines.
Carriers on this route performed within a couple of percentage points of each other.
Other ways to fly Los Angeles to Salt Lake City
Airport pairs in the same two city markets, as the DOT defines them.
| Route | Flights | On time | Cancelled | Median delay | Score |
|---|---|---|---|---|---|
| LAX→SLC Los Angeles to Salt Lake City | 13,286 | 88.2% | 0.32% | -10 min | 87 |
| ONT→SLC this route Ontario to Salt Lake City | 3,726 | 91.8% | 1.05% | -13 min | 84 |
Flying to SLC from the Los Angeles area? Compare ONT, LAX, SNA, BUR for SLC, with the same test for what counts as a real difference.
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Monday the least, a gap of 5.4 percentage points.
By month
- Jan: 87.9%
- Feb: 88.7%
- Mar: 90.3%
- Apr: 90.1%
- May: 91.6%
- Jun: 94.1%
- Jul: 91.5%
- Aug: 90.9%
- Sep: 94.0%
- Oct: 94.4%
- Nov: 95.4%
- Dec: 92.4%
January is historically the weakest month and November the strongest, a spread of 7.5 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: too few flights to score (100)
- August 2023: too few flights to score (93)
- September 2023: too few flights to score (90)
- October 2023: too few flights to score (93)
- November 2023: too few flights to score (89)
- December 2023: too few flights to score (107)
- January 2024: too few flights to score (95)
- February 2024: too few flights to score (78)
- March 2024: too few flights to score (88)
- April 2024: too few flights to score (107)
- May 2024: too few flights to score (118)
- June 2024: too few flights to score (119)
- July 2024: 89.4% from 123 flights
- August 2024: too few flights to score (110)
- September 2024: too few flights to score (99)
- October 2024: too few flights to score (94)
- November 2024: too few flights to score (88)
- December 2024: too few flights to score (94)
- January 2025: too few flights to score (97)
- February 2025: too few flights to score (81)
- March 2025: too few flights to score (91)
- April 2025: too few flights to score (90)
- May 2025: too few flights to score (113)
- June 2025: too few flights to score (114)
- July 2025: too few flights to score (116)
- August 2025: too few flights to score (118)
- September 2025: too few flights to score (110)
- October 2025: too few flights to score (115)
- November 2025: too few flights to score (88)
- December 2025: too few flights to score (90)
- January 2026: too few flights to score (92)
- February 2026: too few flights to score (89)
- March 2026: too few flights to score (94)
- April 2026: too few flights to score (99)
- May 2026: too few flights to score (115)
- June 2026: too few flights to score (113)
- July 2026: too few flights to score (116)
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 91.6% against 93.7% in the 12 months before — declining by 2.1 percentage points.
Data and methodology
Calculated by FlyerIntel from 3,726 ONT → SLC 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