Best Time to Fly SAN to ORD: On-Time Stats by Hour & Airline
San Diego International → Chicago O'Hare International
Data through July 2026 · Last updated October 18, 2026
3,869 flights were scheduled from San Diego (SAN) to Chicago (ORD) in the last 12 months, and 78.1% of those that flew arrived on time, 0.5 points above the US average of 77.6%.
United Airlines was the most punctual of the 3 airlines on the route at 81.3%, while Alaska Airlines trailed at 72.0%.
September has been the best month (86% on time) and Sunday the weakest day of the week (76%).
1.3% of flights were cancelled, versus 1.8% nationally.
SAN to ORD on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| United Airlines | 81.3% | 80 min | 0.5% | 1,673 |
| American Airlines | 78.2% | 93 min | 1.7% | 1,389 |
| Alaska Airlines | 72.0% | 62 min | 2.3% | 777 |
| Frontier Airlines | Limited data | 30 | ||
80%+ good 70–79.9% fair <70% poor
Best time of day to fly SAN to ORD
On-time arrival % by scheduled departure hour (local time), 6,891 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | 88.6% | 1.3% | 989 |
| 7am–8am | 86.2% | 0.8% | 630 |
| 8am–9am | 76.8% | 2.5% | 204 |
| 9am–10am | 84.4% | 0.0% | 46 |
| 10am–11am | 82.5% | 0.3% | 880 |
| 11am–12pm | 76.0% | 1.1% | 181 |
| 12pm–1pm | 66.5% | 1.9% | 208 |
| 1pm–2pm | 65.2% | 1.5% | 685 |
| 2pm–3pm | 68.8% | 0.0% | 799 |
| 3pm–4pm | 71.4% | 2.4% | 207 |
| 4pm–5pm | 71.7% | 1.5% | 405 |
| 5pm–6pm | 79.5% | 1.2% | 519 |
| 6pm–7pm | Limited data | 9 | |
| 7pm–8pm | Limited data | 10 | |
| 10pm–11pm | 93.2% | 1.0% | 1,119 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on SAN to ORD
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 75.5% | -6.9 pts | 7.5% | 120 |
| Christmas & New Year (Dec 20 - Jan 3) | 75.8% | -6.5 pts | 1.1% | 281 |
| Summer peak (Jun 15 - Aug 15) | 73.5% | -8.8 pts | 1.1% | 1,420 |
| All other days | 82.3% | — | 0.8% | 5,070 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).