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Route on-time record

ONT to SLC: most on-time flights and the best time to fly

Ontario (Ontario International Airport) to Salt Lake City (Salt Lake City International Airport). 1,240 nonstop flights in Jun 2025 to May 2026, 91% arrived within 15 minutes and 1.0% were cancelled. The most reliable flight number was Delta 1302 at 9:50 AM.

Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.

ONT → SLC

Ontario to Salt Lake City: 1,240 nonstop flights a year

On time (12 months)

91%

Cancelled

1.0%

avg delay 8 min

Best time to leave

9 AM to noon

97% on time vs 86% noon to 3 PM

Most reliable airline

SkyWest

91% chance on time

Check ONT to SLC fares

Lowest nonstop fare seen in the next two months: $329 (Southwest 2424 on 2026-10-30). Fares open on our travel partner (Aviasales). Pick the flight number you chose here.

Most reliable nonstop flights

Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.

  1. #1 · Delta 1302

    9:50 AM → 12:40 PM1h 50m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    95%

    chance on time

    On time (history)
    100%
    Cancelled
    5.0%
    Avg arrival delay
    0 min
    • Arrived on time 100% of the time (19 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (9 AM to noon: 97% on time; Noon to 3 PM: 86%).
    • Short track record (19 flights), so its score leans on the airline's record at this hour.

    Limited track record · 19 flights

    Find Delta 1302 fares Opens this date on Aviasales

  2. #2 · Delta 2708

    6:00 AM → 8:50 AM1h 50m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    95%

    chance on time

    On time (history)
    95%
    Cancelled
    0.5%
    Avg arrival delay
    6 min
    • Arrived on time 95% of the time (363 flights, Jun 2025 to May 2026).

    Strong track record · 363 flights

    Find Delta 2708 fares Opens this date on Aviasales

  3. #3 · SkyWest 3762 · sold as United Express, Delta Connection, American Eagle or Alaska

    4:57 PM → 7:49 PM1h 52m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    92%

    chance on time

    On time (history)
    96%
    Cancelled
    0.0%
    Avg arrival delay
    2 min
    • Arrived on time 96% of the time (25 flights, Jun 2025 to May 2026).
    • Short track record (25 flights), so its score leans on the airline's record at this hour.

    Limited track record · 25 flights

    Find 4:57 PM flight fares Opens this date on Aviasales

  4. #4 · SkyWest 3809 · sold as United Express, Delta Connection, American Eagle or Alaska

    5:05 PM → 8:00 PM1h 55m nonstop

    Local times, typical schedule. Last flown 2026-05-06. Same departure also flew as SkyWest 3829; its record covers all of them.

    91%

    chance on time

    On time (history)
    90%
    Cancelled
    0.0%
    Avg arrival delay
    6 min
    • Arrived on time 90% of the time (60 flights, Jun 2025 to May 2026).
    • Never cancelled in 60 scheduled flights.

    Moderate track record · 60 flights

    Find 5:05 PM flight fares Opens this date on Aviasales

  5. #5 · Frontier 1122

    9:12 AM → 12:04 PM1h 50m nonstop

    Local times, typical schedule. Last flown 2026-05-04.

    90%

    chance on time

    On time (history)
    83%
    Cancelled
    0.0%
    Avg arrival delay
    7 min
    • Arrived on time 83% of the time (24 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (9 AM to noon: 97% on time; Noon to 3 PM: 86%).
    • Short track record (24 flights), so its score leans on the airline's record at this hour.

    Limited track record · 24 flights

    Find Frontier 1122 fares Opens this date on Aviasales

  6. #6 · Delta 1006

    1:29 PM → 4:18 PM1h 49m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    89%

    chance on time

    On time (history)
    96%
    Cancelled
    0.0%
    Avg arrival delay
    3 min
    • Arrived on time 96% of the time (25 flights, Jun 2025 to May 2026).
    • Leaves in this route's least on-time window (Noon to 3 PM: 86% on time; 9 AM to noon: 97%).
    • Short track record (25 flights), so its score leans on the airline's record at this hour.

    Limited track record · 25 flights

    Find Delta 1006 fares Opens this date on Aviasales

  7. #7 · Delta 475

    1:20 PM → 4:09 PM1h 49m nonstop

    Local times, typical schedule. Last flown 2026-05-06.

    83%

    chance on time

    On time (history)
    82%
    Cancelled
    1.6%
    Avg arrival delay
    16 min
    • Arrived on time 82% of the time (119 flights, Jun 2025 to May 2026).
    • Leaves in this route's least on-time window (Noon to 3 PM: 86% on time; 9 AM to noon: 97%).

    Moderate track record · 119 flights

    Find Delta 475 fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

  • SkyWest Airlines (sold as United Express, Delta Connection, American Eagle or Alaska)91%

    304 flights · 92% on time as flown · 0.5% cancel

  • Delta Air Lines90%

    906 flights · 91% on time as flown · 1.2% cancel

  • Frontier Airlines89%

    30 flights · 87% on time as flown · 0.8% cancel

On time by departure time

All airlines, scheduled local departure, Jun 2025 to May 2026.

  • Before 9 AM95%

    368 flights · avg delay 6 min

  • 9 AM to noon97%

    163 flights · avg delay 4 min

  • Noon to 3 PM86%

    365 flights · avg delay 11 min

  • 3 to 6 PM92%

    340 flights · avg delay 8 min

Best day: Tuesday (95%). Worst: Monday (90%).

On time by month

All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.

J
88
F
89
M
90
A
90
M
92
J
91
J
92
A
91
S
94
O
94
N
95
D
92

What delays this route

  • Airline (crew, maintenance, boarding)54%
  • Late-arriving aircraft39%
  • Severe weather4%
  • Air traffic control and airport volume3%

Share of delay minutes by the cause airlines report to the US DOT.

Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure

ONT to SLC questions

What time of day is best to fly ONT to SLC?
9 AM to noon: 97% of flights arrived on time, against 86% for departures noon to 3 PM.
Which airline is most on time from ONT to SLC?
SkyWest, with a season-adjusted 91% chance of operating and arriving on time over 304 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
What is the worst month for delays on ONT to SLC?
January (88% on time); the best was November (95%), averaged over Jun 2023 to May 2026.
Is this a prediction for my flight?
No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.

More routes from ONT

Live status: FAA delays and ground stops