Chicago (ORD) to San Diego (SAN): On-Time Performance
Data through May 2026
When you fly ORD to SAN matters as much as anything else about the booking: the route swung from 83% on-time in May 2025 to just 63% in April 2026. Across the full period the route averages 74% on-time against a national 78%. Morning departures also hold up better than evening ones (81% vs 62%), which matters most in the rough months.
- On-time
- 74%
- arrived <15 min late
- Avg delay
- 20 min
- completed flights
- Cancelled
- 1.0%
- Flights/day
- 10
- last 12 months
- Duration
- 4h 29m
- scheduled
- Distance
- 1,723 mi
Best airline from ORD to SAN
4 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| United Airlinesmost reliable | 78% | 16 min | 0.5% | 3,436 |
| American Airlines | 69% | 24 min | 1.3% | 2,553 |
| Alaska Airlines | 69% | 23 min | 2.5% | 605 |
| Frontier Airlines | 46% | 52 min | 1.2% | 81 |
Monthly on-time trend
Best time to fly from ORD to SAN
Aim for departures around 6 a.m. (90% on-time); avoid 9 p.m. departures (53%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 73% | 22 min |
| Tuesday | 77% | 16 min |
| Wednesday | 75% | 18 min |
| Thursday | 71% | 18 min |
| Friday | 69% | 26 min |
| Saturdaybest | 78% | 15 min |
| Sunday | 72% | 22 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft41%
- Airline operations33%
- National airspace system21%
- Weather5%
Frequently asked questions
- How often are flights from ORD to SAN delayed?
- 27% of ORD–SAN flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 20 minutes.
- Which airline is most reliable from ORD to SAN?
- United Airlines has the best on-time record on this route at 78%, based on 3,436 flights. 4 airlines flew ORD–SAN frequently enough to compare in this period.
- What is the best time of day to fly from ORD to SAN?
- Departures around 6 a.m. have the best record (90% on-time), while departures around 9 p.m. have the worst (53%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from ORD to SAN?
- The scheduled ORD–SAN flight time averages 4h 29m over 1,723 miles. Actual arrival times vary — flights on this route land 15+ minutes late 27% of the time.
- How often are ORD to SAN flights cancelled?
- 1% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
- What is the worst month to fly from ORD to SAN?
- April 2026 was the roughest month in this dataset, with only 63% of arrivals on time. The best was May 2025 at 83%. If your dates are flexible, that 20-point gap is worth planning around.
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Based on 6,676 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.