Flight history · Aug 2025 – Jul 2026 · US DOT on-time records
WN 3911 · Boston (BOS) → Chicago (MDW)
Sold by Southwest. Still flying: 48 of the last 56 days (Mon–Sat).
Arrives on time43%within 15 minutes, of 51 flights
Cancelled5.9%of scheduled flights
An hour or more late26%of flights that operated
When late, on average73 minlate, among flights 15+ min late
Schedule
Typical times in the Jun 6 – Jul 31, 2026 schedule, local at each airport (Chicago is 1 h behind Boston).
- Leaves BOS
- 18:15
- Arrives MDW
- 20:05
- Flight time
- 2h 50m
- Days flown, last 8 weeks
- 48 of 56
Each square is a day, Sat Jun 6 to Fri Jul 31, two weeks per row (each column is the same weekday); filled = flew.
How late it arrives
Share of flights that operated arriving more than this late.
Horizontal: minutes late at arrival (0 to 3 hours). Vertical: share of flights later than that.
Its hour at BOS
All flights leaving Boston (BOS) at 6–7 pm, wherever they’re going: 61% left within 15 minutes and 3.3% were cancelled (8,676 flights in the year). Other Southwest flights on this route →
Upcoming forecasts
Our odds that this flight is late or cancelled on the days we publish.