ON TIMEBOARD

BWI → MDW on time

Baltimore/Washington (Baltimore, MD) to Chicago Midway (Chicago, IL). Every scheduled flight, September 2025 to August 2026.

On time
73%
arrived < 15 min late
Cancelled
2.4%
1,824 flights
Typical arrival
−3 min
median vs schedule
When late
+60 min
average delay
Flights / day
5
2 airlines

73% of flights from Baltimore to Chicago arrived on time over the past 12 months. That is worse than the typical U.S. route. The 6 a.m. departures ran on time 93% of the time; the 8 p.m. ones 50%. 11% of flights arrived more than an hour late or not at all.

How late?

The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for BWI → MDW: when a flight was late, it was under 45 minutes late 56% of the time. About 1 in 13 flights landed an hour or more late, and 1 in 96 three hours or more; 2.4% were cancelled outright.

Share of all 1,824 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
Southwest Airlines1,76873%2.4%−3 min7.4%+60 minSouthwest Airlines
Frontier Airlines56—————Frontier Airlines

Airline = the name on the ticket. Regional flights (e.g. "Delta Connection") count under the ticketing airline, and the operator is listed.

Best time of day to fly

On-time rate by scheduled departure hour (local time at BWI). Delays build through the day as late planes knock on, so early flights usually do best.

40%70%100%6 a.m. departures: 93% on time (193 flights)936a7 a.m. departures: 84% on time (144 flights)847a8 a.m. departures: too few flights (67 flights)8a9 a.m. departures: 78% on time (103 flights)789a10 a.m. departures: 77% on time (113 flights)7710a11 a.m. departures: too few flights (50 flights)11anoon departures: too few flights (84 flights)12p1 p.m. departures: 83% on time (116 flights)831p2 p.m. departures: too few flights (91 flights)2p3 p.m. departures: too few flights (75 flights)3p4 p.m. departures: 72% on time (128 flights)724p5 p.m. departures: 65% on time (124 flights)655p6 p.m. departures: too few flights (78 flights)6p7 p.m. departures: 62% on time (199 flights)627p8 p.m. departures: 50% on time (117 flights)508p9 p.m. departures: too few flights (84 flights)9p10 p.m. departures: too few flights (58 flights)10p
BWI → MDW, share of flights arriving on time, by departure hour. Hours with under 100 flights are greyed out.
82%+ on time76–82%68–76%under 68%too few flights

By airline and hour

DepartsSouthwest Airlines
6 a.m.93%
7 a.m.84%
9 a.m.78%
10 a.m.77%
1 p.m.83%
4 p.m.73%
5 p.m.62%
7 p.m.61%
8 p.m.50%

Last flight of the day

On BWI → MDW, each airline's last flight of the day was cancelled 3.8% of the time, against 2.0% for its earlier flights (1.9× as often). It arrived 3+ hours late 1.1% of the time (earlier flights: 1.0%). It matters more than the numbers suggest. Miss an earlier flight and there's another one that evening; miss the last one and you're usually waiting until morning.

AirlineLast departureLast: cancelledLast: 3h+ lateEarlier: cancelledNext morning
Southwest Airlines8:55 p.m.3.8%1.1%2.0%first flight 6:30 a.m.

Last flight = the airline's last scheduled departure on this route that day, on days it flies the route at least twice; past 12 months. Times are typical scheduled times over the latest three months.

If you need to be in MDW tonight, book an earlier flight so there's a backup if it's cancelled.

By month

Each calendar month pooled over 2023–2026. Best: February (86%). Worst: July (60%).

40%70%100%Jan: 76% on time (400 flights)76JanFeb: 86% on time (352 flights)86FebMar: 72% on time (405 flights)72MarApr: 80% on time (465 flights)80AprMay: 71% on time (510 flights)71MayJun: 70% on time (535 flights)70JunJul: 60% on time (563 flights)60JulAug: 67% on time (535 flights)67AugSep: 83% on time (525 flights)83SepOct: 79% on time (559 flights)79OctNov: 81% on time (465 flights)81NovDec: 75% on time (447 flights)75Dec

By day of week

DayFlightsOn timeCancelled
Monday28770%2.4%
Tuesday24174%2.1%
Wednesday23879%0.8%
Thursday27172%1.8%
Friday28073%2.5%
Saturday21972%3.2%
Sunday28870%3.5%

Why flights were late

Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.

Late inbound plane 44%Airline (crew, maintenance, ops) 28%Air traffic & airport (NAS) 20%Severe weather 7%

Cancellations: weather 31 · airline 9 · air traffic/airport 3

Month by month

50%75%100%Sep 2023Jan 2024Jan 2025Jan 2026Sep 2023: 82% on time, 1.8% cancelledOct 2023: 76% on time, 0.5% cancelledNov 2023: 81% on time, 0.7% cancelledDec 2023: 79% on time, 2.6% cancelledJan 2024: 67% on time, 10.0% cancelledFeb 2024: 93% on time, 0.0% cancelledMar 2024: 73% on time, 1.4% cancelledApr 2024: 76% on time, 0.6% cancelledMay 2024: 60% on time, 0.0% cancelledJun 2024: 72% on time, 0.0% cancelledJul 2024: 62% on time, 0.5% cancelledAug 2024: 66% on time, 1.1% cancelledSep 2024: 83% on time, 0.0% cancelledOct 2024: 83% on time, 0.0% cancelledNov 2024: 87% on time, 0.6% cancelledDec 2024: 80% on time, 0.7% cancelledJan 2025: 78% on time, 4.9% cancelledFeb 2025: 86% on time, 0.0% cancelledMar 2025: 77% on time, 0.0% cancelledApr 2025: 83% on time, 0.6% cancelledMay 2025: 76% on time, 0.5% cancelledJun 2025: 69% on time, 0.0% cancelledJul 2025: 59% on time, 4.3% cancelledAug 2025: 73% on time, 0.5% cancelledSep 2025: 86% on time, 0.5% cancelledOct 2025: 77% on time, 0.0% cancelledNov 2025: 75% on time, 6.3% cancelledDec 2025: 64% on time, 1.5% cancelledJan 2026: 82% on time, 3.9% cancelledFeb 2026: 79% on time, 3.4% cancelledMar 2026: 65% on time, 4.0% cancelledApr 2026: 81% on time, 0.8% cancelledMay 2026: 79% on time, 0.0% cancelledJun 2026: 68% on time, 1.2% cancelledJul 2026: 60% on time, 5.0% cancelledAug 2026: 62% on time, 2.4% cancelled
Share of flights on time, by month (hover a point for cancellations)
BWI → MDW, monthly on-time and cancellation rate.

Worst days in the past year

DateFlightsOn timeCancelled
Nov 29, 202570%5
Jul 28, 202660%1
Dec 26, 202550%2
Jan 25, 202640%4
Aug 1, 202640%0

Nearby airport alternatives

Other ways to make the same trip, using airports within 60 miles of Baltimore or Chicago. None has been clearly more reliable than BWI → MDW.

RouteFlightsOn timeCancelled
BWI → MDW (this route)1,82473%2.4%
IAD → ORD Washington Dulles to Chicago O'Hare2,10674%0.9%
BWI → ORD Baltimore/Washington to Chicago O'Hare2,67773%2.5%
DCA → MDW Washington Reagan National to Chicago Midway2,09973%2.8%
DCA → ORD Washington Reagan National to Chicago O'Hare7,11271%3.6%

Questions

How often are flights from BWI to MDW on time?

73% of 1,824 scheduled flights from Baltimore, MD to Chicago, IL arrived within 15 minutes of schedule between September 2025 and August 2026. 2.4% were cancelled.

What is the best time of day to fly BWI to MDW?

Flights scheduled to leave at 6 a.m. were the most reliable (93% on time). The 8 p.m. departures were the least (50%).

What month has the most delays from BWI to MDW?

July (60% on time). The best month is February (86%), over 2023–2026.

Is the last flight of the day from BWI to MDW more likely to be cancelled?

Yes. Each airline's last BWI–MDW flight of the day was cancelled 3.8% of the time over the past year, against 2.0% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.

Related

Domestic flights by the airlines that report to the U.S. DOT, plus their regional partners. "On time" means arriving less than 15 minutes after schedule; cancelled and diverted flights count as not on time. Past performance is a guide, not a forecast. Method.