Best Time to Fly SAN to MDW: On-Time Stats by Hour & Airline
San Diego International → Chicago Midway International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 77.6% of San Diego (SAN) to Chicago (MDW) flights arrived on time (1,093 scheduled flights). That is in line with the national average of 77.6%.
Southwest Airlines was the only reporting airline with regular flights on this route.
Over 24 months, Saturday was the most reliable day (86% on time) and July the worst month (68%).
The cancellation rate was 1.0% (US average 1.8%).
SAN to MDW 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 |
|---|---|---|---|---|
| Southwest Airlines | 77.6% | 47 min | 1.0% | 1,093 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly SAN to MDW
On-time arrival % by scheduled departure hour (local time), 2,095 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | 91.1% | 0.9% | 435 |
| 7am–8am | 87.6% | 1.4% | 148 |
| 8am–9am | 81.7% | 0.0% | 110 |
| 9am–10am | Limited data | 9 | |
| 10am–11am | 80.5% | 0.9% | 116 |
| 11am–12pm | 73.5% | 0.4% | 252 |
| 12pm–1pm | 70.5% | 0.0% | 129 |
| 1pm–2pm | 66.7% | 1.2% | 86 |
| 2pm–3pm | 65.6% | 0.0% | 61 |
| 3pm–4pm | 56.3% | 1.1% | 88 |
| 4pm–5pm | 78.1% | 0.0% | 106 |
| 5pm–6pm | 69.8% | 0.0% | 202 |
| 6pm–7pm | 61.5% | 1.3% | 158 |
| 7pm–8pm | 60.0% | 2.2% | 46 |
| 10pm–11pm | 95.2% | 2.7% | 149 |
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 MDW
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) | 81.8% | +1.3 pts | 2.8% | 36 |
| Christmas & New Year (Dec 20 - Jan 3) | 62.7% | -17.9 pts | 2.6% | 78 |
| Summer peak (Jun 15 - Aug 15) | 69.6% | -10.9 pts | 1.0% | 402 |
| All other days | 80.5% | — | 0.6% | 1,579 |
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).