Route reliability record
MKE→BWI
Milwaukee to Baltimore
- Flights
- 828
- Period
- July 2025 to June 2026
- Distance
- 641 mi
- Carriers
- 2
This route earns a B. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 828 MKE to BWI flights, with a median arrival 7 minutes early.
Best time to fly MKE to BWI: a 11am–2pm departure, ideally on a Tuesday. Flights in that window arrived on time 93.2% of the time and Tuesday flights 90.4%, against 84.3% for the route overall.
Set against the rest of the country, this route's record is 7 points better than the US average of 77.6%. That gap is worth roughly 67 fewer late arrivals for every thousand flights.
Key figures
On time
84.3%
Arrivals under 15 minutes late, of 814 completed flights
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
1.57%
National rate is 1.81%
Best carrier
Southwest
84.2% on time across 826 flights
These figures cover 828 flights between July 2025 and June 2026. The median arrival is 7 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
Which airline is most reliable on MKE to BWI
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Spirit Airlinesthin sample | 2 | 100.0% | — | 0.00% | A+ |
| Southwest Airlines | 826 | 84.2% | 66 min | 1.57% | B |
Best ways to make this trip
The most reliable ways to fly Milwaukee to Baltimore
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 2 of the top 3 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. MKE → BWIMilwaukee to Baltimore | Southwest Airlines | 82.9% | 84.2% | 1.57% | 11am–2pm, Tue (route) | — |
| 2. MKE → DCAMilwaukee to Washington | Southwest Airlines | 73.7% | 75.1% | 1.90% | 8am–11am, Mon | — |
| 3. MKE → DCAMilwaukee to Washington | PSA Airlines | 71.7% | 75.8% | 5.46% | 5am–8am, Sat | OH 5646 06:00 |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 38 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am312 flights92.9%
- 8am–11am54 flights92.3%
- 11am–2pm133 flights93.2%
- 2pm–5pm171 flights85.3%
- 5pm–8pm158 flights55.0%
- 8pm–5am—
Scale runs 45% to 100%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 55.0% on time, against 93.2% for the 11am–2pm slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5am–8am window is the busiest, with 312 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 19 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
June is the worst month at 75.6% on time, 19 points below April, the best at 94.9%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. July was the busiest month here, with 90 flights.
Across the week, Tuesday is the strongest day at 90.4% on time and Sunday the weakest at 75.6%. 15 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 51% of the 8,201 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 51%Late-arriving aircraft
- 24%Carrier
- 23%National Airspace System
- 2%Extreme weather
51% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 8,201 reported delay minutes here, that single category outweighs weather by 30 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 8,201 reported delay minutes.
Cancellations sit at 1.57% against a national 1.81%, which is ordinary. Diversions add another 0.12%.
Connections and stage length
What a delay here actually costs
5.2% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.
The 641 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 76.1% on time across 832 flights, 8 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 8 points of difference.
One caution: this is a thin sample. 828 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
Work out the risk of missing a connection in BWI after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 828 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 84.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 814 completed flights over 12 months sit behind that.
Common questions
MKE to BWI questions
How often is MKE to BWI delayed?
About one flight in six arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 15.7% of the 828 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is MKE to BWI compared with the rest of the country?
84.3% of flights arrive on time here against a national 77.6%, a difference of 7 points in its favour. That is worth a B on this site's grading scale.
What time of day has the fewest delays on MKE to BWI?
The 11am–2pm departure window is the strongest at 93.2% on time. The 5pm–8pm window is the weakest at 55.0%, 38 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are June delays on MKE to BWI?
June is the weakest month at 75.6% on time, compared with 94.9% in April. Across the year that is 19 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- BWI to MKE — the return legseparate record
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- MKE to ORD, a related route67.4%
- ATL to BWI, a related route75.6%
- MKE to DEN, a related route78.1%
- Spirit Airlines on-time record100.0%
- Southwest Airlines on-time record84.2%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. MKE to BWI and BWI to MKE are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.