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Route on-time record

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

Austin (Austin Bergstrom International Airport) to Ontario (Ontario International Airport). 335 nonstop flights in Jun 2025 to May 2026, 76% arrived within 15 minutes and 0.3% were cancelled. The most reliable flight number was Southwest 419 at 1:15 PM.

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

AUS → ONT

Austin to Ontario: 335 nonstop flights a year

On time (12 months)

76%

Cancelled

0.3%

avg delay 13 min

Best time to leave

Noon to 3 PM

84% on time vs 68% 3 to 6 PM

Most reliable airline

Southwest

76% chance on time

Check AUS to ONT fares

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 · Southwest 419

    1:15 PM → 2:25 PM3h 10m nonstop

    Local times, typical schedule. Last flown 2026-05-29.

    83%

    chance on time

    On time (history)
    85%
    Cancelled
    0.0%
    Avg arrival delay
    8 min
    • Arrived on time 85% of the time (39 flights, Jun 2025 to May 2026).
    • Never cancelled in 39 scheduled flights.
    • Leaves in this route's most on-time window (Noon to 3 PM: 84% on time; 3 to 6 PM: 68%).
    • Departs inside AUS's trouble window: 79% of its 91 ground stops and delay programs started between 10 AM and 4 PM.

    Limited track record · 39 flights

    Find Southwest 419 fares Opens this date on Aviasales

  2. #2 · Southwest 2167

    2:00 PM → 3:20 PM3h 15m nonstop

    Local times, typical schedule. Last flown 2026-04-06.

    79%

    chance on time

    On time (history)
    85%
    Cancelled
    0.0%
    Avg arrival delay
    7 min
    • Arrived on time 85% of the time (33 flights, Jun 2025 to May 2026).
    • Never cancelled in 33 scheduled flights.
    • Leaves in this route's most on-time window (Noon to 3 PM: 84% on time; 3 to 6 PM: 68%).
    • Departs inside AUS's trouble window: 79% of its 91 ground stops and delay programs started between 10 AM and 4 PM.

    Limited track record · 33 flights

    Find Southwest 2167 fares Opens this date on Aviasales

  3. #3 · Southwest 3932

    4:35 PM → 5:45 PM3h 10m nonstop

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

    62%

    chance on time

    On time (history)
    25%
    Cancelled
    0.0%
    Avg arrival delay
    31 min
    • Arrived on time 25% of the time (8 flights, Jun 2025 to May 2026).
    • Leaves in this route's least on-time window (3 to 6 PM: 68% on time; Noon to 3 PM: 84%).
    • Departs outside AUS's trouble window (10 AM to 4 PM, when 79% of its 91 ground stops and delay programs started).
    • Short track record (8 flights), so its score leans on the airline's record at this hour.

    Limited track record · 8 flights

    Find Southwest 3932 fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

  • Southwest Airlines76%

    335 flights · 76% on time as flown · 0.3% cancel

On time by departure time

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

  • Noon to 3 PM84%

    138 flights · avg delay 9 min

  • 3 to 6 PM68%

    144 flights · avg delay 17 min

  • 6 to 9 PM76%

    34 flights · avg delay 13 min

Best day: Tuesday (85%). Worst: Sunday (62%).

Smarter routing

Nearby airports that run more on time

  • AUS → LAX 81% chance on time

    Austin Bergstrom International Airport to Los Angeles International Airport · 4,074 flights a year · 47 mi from your airports · yours: 76%

    Rank flightsFares

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
82
F
79
M
80
A
78
M
64
J
46
J
69
A
77
S
63
O
78
N
73
D
77

What delays this route

  • Late-arriving aircraft58%
  • Airline (crew, maintenance, boarding)27%
  • Air traffic control and airport volume13%
  • Severe weather1%

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

Finding the most reliable connections from AUS to ONT…

AUS to ONT questions

What time of day is best to fly AUS to ONT?
Noon to 3 PM: 84% of flights arrived on time, against 68% for departures 3 to 6 PM.
Which airline is most on time from AUS to ONT?
Southwest, with a season-adjusted 76% chance of operating and arriving on time over 335 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 AUS to ONT?
June (46% on time); the best was January (82%), 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 AUS

Live status: FAA delays and ground stops