Route reliability record
LAX→MDW
Los Angeles to Chicago
- Flights
- 1,328
- Period
- July 2025 to June 2026
- Distance
- 1,751 mi
- Carriers
- 1
This route lands a B+, about a point better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 45 minutes on average. That is a workable record, not a spotless one. That rests on 1,328 LAX to MDW flights, with a median arrival 3 minutes early.
Best time to fly LAX to MDW: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 91.1% of the time and Wednesday flights 86.3%, against 79.0% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
79.0%
Arrivals under 15 minutes late, of 1,311 completed flights
Avg delay
45 min
Across delayed arrivals only, not all flights
Cancelled
0.53%
National rate is 1.81%
Best carrier
Southwest
79.0% on time across 1,328 flights
These figures cover 1,328 flights between July 2025 and June 2026. The median arrival is 3 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 LAX to MDW
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 |
|---|---|---|---|---|---|
| Southwest Airlines | 1,328 | 79.0% | 45 min | 0.53% | B+ |
Best ways to make this trip
The most reliable ways to fly Los Angeles to Chicago
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. 4 of the top 5 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. LAX → ORDLos Angeles to Chicago | United Airlines | 79.9% | 80.5% | 0.74% | 5am–8am, Tue | UA 212 17:00 |
| 2. LAX → MDWLos Angeles to Chicago | Southwest Airlines | 78.6% | 79.0% | 0.53% | 5am–8am, Wed | — |
| 3. SNA → ORDSanta Ana to Chicago | United Airlines | 78.5% | 79.0% | 0.58% | 5am–8am, Tue | — |
| 4. SNA → ORDSanta Ana to Chicago | American Airlines | 73.3% | 74.6% | 1.79% | 5am–8am, Tue | AA 2590 07:45 |
| 5. LAX → ORDLos Angeles to Chicago | American Airlines | 71.2% | 72.9% | 2.33% | 5am–8am, Tue | — |
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 43 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–8am365 flights91.1%
- 8am–11am125 flights80.0%
- 11am–2pm251 flights67.3%
- 2pm–5pm172 flights62.5%
- 5pm–8pm50 flights48.0%
- 8pm–5am365 flights86.7%
Scale runs 40% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 48.0% on time, against 91.1% 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 365 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 23 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.
September is the best month on the calendar at 89.7% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. July was the busiest month here, with 146 flights.
Across the week, Wednesday is the strongest day at 86.3% on time and Sunday the weakest at 74.0%. 12 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. Carrier accounts for 44% of the 12,000 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.
- 44%Carrier
- 39%Late-arriving aircraft
- 16%National Airspace System
- 1%Extreme weather
- 0%Security
39% 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 12,000 reported delay minutes here, that single category outweighs weather by 39 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 12,292 reported delay minutes.
The largest share of delay minutes, 44%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 5,421 of the 12,000 delay minutes reported here.
Cancellations are rare at 0.53%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here actually costs
Badly late arrivals are rare here: only 4.0% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
At 1,751 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 68.9% on time across 1,328 flights, 10 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 10 points of difference.
The sample behind these figures is 1,328 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.
Work out the risk of missing a connection in MDW after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 89.7% on time and March 66.7%, a swing of 23 points. If the dates move at all, move them out of March before you think about anything else. 1,311 completed flights over 12 months sit behind that.
Common questions
LAX to MDW questions
How often is LAX to MDW 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 21.0% of the 1,328 flights in this analysis, against 22.4% nationally. Delayed flights are late by about 45 minutes on average.
How reliable is LAX to MDW compared with the rest of the country?
79.0% of flights arrive on time here against a national 77.6%, a difference of about a point in its favour. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on LAX to MDW?
The 5am–8am departure window is the strongest at 91.1% on time. The 5pm–8pm window is the weakest at 48.0%, 43 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 March delays on LAX to MDW?
March is the weakest month at 66.7% on time, compared with 89.7% in September. Across the year that is 23 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
- MDW to LAX — the return legseparate record
- Los Angeles International (LAX) delay statistics
- Chicago Midway International (MDW) delay statistics
- LAX to SFO, a related route64.8%
- ATL to MDW, a related route76.3%
- LAX to JFK, a related route79.1%
- Southwest Airlines on-time record79.0%
- 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. LAX to MDW and MDW to LAX are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Embed LAX to MDW’s on-time badge on your site
Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.
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.