Best Time to Fly PDX to MDW: On-Time Stats by Hour & Airline
Portland International → Chicago Midway International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 89.6% of Portland (PDX) to Chicago (MDW) flights arrived on time (684 scheduled flights). That is 12.0 points above 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 (95% on time) and June the worst month (81%).
The cancellation rate was 0.7% (US average 1.8%).
PDX 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 | 89.6% | 40 min | 0.7% | 684 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly PDX to MDW
On-time arrival % by scheduled departure hour (local time), 1,284 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 94.7% | 1.0% | 193 |
| 6am–7am | 94.7% | 0.2% | 399 |
| 7am–8am | Limited data | 16 | |
| 8am–9am | 91.9% | 0.0% | 87 |
| 9am–10am | 93.8% | 0.0% | 96 |
| 10am–11am | 89.7% | 0.0% | 39 |
| 11am–12pm | 73.0% | 0.0% | 75 |
| 12pm–1pm | Limited data | 24 | |
| 1pm–2pm | 74.8% | 0.0% | 119 |
| 2pm–3pm | 56.9% | 0.0% | 65 |
| 3pm–4pm | Limited data | 19 | |
| 6pm–7pm | Limited data | 2 | |
| 11pm–12am | 92.5% | 2.0% | 150 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on PDX 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) | Limited data | 15 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 83.3% | -8.4 pts | 0.0% | 30 |
| Summer peak (Jun 15 - Aug 15) | 80.7% | -11.1 pts | 0.6% | 346 |
| All other days | 91.8% | — | 0.5% | 893 |
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).