Carrier performance at one airport
WN→MKE
Southwest Airlines at Milwaukee Mitchell International
- Departures
- 10,080
- Period
- September 2025 to August 2026
- Routes
- 16
- Rank here
- #3 of 8
Southwest Airlines at Milwaukee lands a B+, 3 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 55 minutes on average. That rests on 10,080 flights, of which Delta Air Lines flew 3,668 at 86.8% on time.
Measured against the airport rather than the country, Southwest Airlines runs 2 points ahead of the 78.2% weighted average across all carriers at MKE. That is the comparison worth making: every operator here works the same runways, the same airspace and the same weather.
Key figures
On time
79.8%
9,952 completed departures
Avg delay
54 min
Across delayed flights only
Cancelled
0.90%
At MKE, this carrier only
Rank here
#3
Of 8 carriers clearing the floor at MKE
These figures cover 10,000 flights between September 2025 and August 2026. The median arrival is 5 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.
Against the competition
Every carrier at MKE, ranked
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 86.8% of the time; SkyWest Airlines manages 72.5%. Sample sizes sit next to every figure, because a two-point gap across 7,650 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 3,668 | 86.8% | 85 min | 1.77% | A |
| Alaska Airlines | 509 | 80.6% | 38 min | 0.39% | B+ |
| Southwest Airlines (this page) | 10,080 | 79.8% | 54 min | 0.90% | B+ |
| Republic Airways | 2,407 | 78.5% | 82 min | 6.02% | B− |
| United Airlines | 686 | 78.2% | 60 min | 0.15% | B+ |
| American Airlines | 2,432 | 76.9% | 113 min | 2.47% | B |
| PSA Airlines | 1,321 | 76.5% | 135 min | 6.81% | B− |
| SkyWest Airlines | 7,650 | 72.5% | 94 min | 3.05% | C− |
PSA Airlines cancels 6.8% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.
Route by route
Where Southwest Airlines flies from MKE
Southwest Airlines operates 16 routes out of MKE with enough volume to report. Route records inside one carrier at one airport still spread widely, because a short shuttle and a transcontinental have very different exposure to a late inbound.
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| MKE to DEN · Denver | 1,248 | 78.9% | 56 min | 0.64% | B+ |
| MKE to MCO · Orlando | 1,187 | 76.9% | 49 min | 0.67% | B+ |
| MKE to LAS · Las Vegas | 1,003 | 81.1% | 53 min | 0.90% | B+ |
| MKE to BNA · Nashville | 976 | 80.7% | 49 min | 1.13% | B |
| MKE to PHX · Phoenix | 953 | 78.3% | 54 min | 0.42% | B+ |
| MKE to BWI · Baltimore | 827 | 84.7% | 74 min | 1.57% | B |
| MKE to STL · St. Louis | 681 | 88.6% | 58 min | 0.88% | A+ |
| MKE to DCA · Washington | 680 | 73.3% | 58 min | 1.76% | C |
| MKE to TPA · Tampa | 452 | 82.5% | 60 min | 1.33% | B |
| MKE to DAL · Dallas | 396 | 82.1% | 62 min | 0.00% | B+ |
| MKE to RSW · Fort Myers | 375 | 80.8% | 61 min | 0.80% | B+ |
| MKE to MDW · Chicagothin sample | 360 | 72.3% | 51 min | 1.67% | C |
| MKE to MCI · Kansas Citythin sample | 354 | 84.1% | 43 min | 0.56% | B+ |
| MKE to AUS · Austinthin sample | 270 | 80.1% | 46 min | 0.74% | B+ |
| MKE to SAN · San Diegothin sample | 211 | 68.9% | 44 min | 0.00% | C+ |
| MKE to FLL · Fort Lauderdalethin sample | 84 | 69.9% | 46 min | 1.19% | C |
Departure window
Best time of day for this operation
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 31 points, against 14 points between the best and worst carrier.
- 5am–8am2,994 flights92.6%
- 8am–11am1,372 flights89.4%
- 11am–2pm1,720 flights80.7%
- 2pm–5pm1,925 flights70.9%
- 5pm–8pm1,757 flights61.8%
- 8pm–5am312 flights63.0%
Scale runs 55% to 100%.
The 5pm–8pm window is where this operation falls apart: 61.8% on time, against 92.6% for the 5am–8am 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 2,994 flights scheduled in it.
Across the year
Seasonal pattern
December is the weak month at 74.4% on time, against 87.1% in September. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. March was the busiest month here, with 999 flights.
Delay causes
What holds this operation up
- 47%Late-arriving aircraft
- 27%National Airspace System
- 24%Carrier
- 2%Extreme weather
- 0%Security
47% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 109,000 reported delay minutes here, that single category outweighs weather by 19 to one. The split is drawn from 109,099 reported delay minutes.
Cancellations sit at 0.90% against a national 1.89%, which is ordinary. Diversions add another 0.37%.
5.2% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 55 minutes, which a normal layover absorbs.
The sample behind these figures is 10,080 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 87.1% on time and December 74.4%, a swing of 13 points. If the dates move at all, move them out of December before you think about anything else. 9,952 completed flights over 12 months sit behind that.
Common questions
Southwest Airlines at MKE
How often is Southwest Airlines at MKE delayed?
About one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 20.2% of the 10,080 flights in this analysis, against 22.7% nationally. Delayed flights are late by about 55 minutes on average.
Which airline is most reliable on Southwest Airlines at MKE?
Delta Air Lines leads at 86.8% on time across 3,668 flights. SkyWest Airlines is at the other end on 72.5%, a gap of 14 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on Southwest Airlines at MKE?
The 5am–8am departure window is the strongest at 92.6% on time. The 5pm–8pm window is the weakest at 61.8%, 31 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 December delays on Southwest Airlines at MKE?
December is the weakest month at 74.4% on time, compared with 87.1% in September. Across the year that is 13 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
- Southwest Airlines network-wide record
- Milwaukee Mitchell International (MKE) all carriers
- MKE to DEN route record78.9%
- MKE to MCO route record76.9%
- MKE to LAS route record81.1%
- MKE to BNA route record80.7%
- Why the first flight of the morning is statistically safest
- Do airlines run better at their own hubs?
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.