Carrier route record
WNLAS→DTW
Southwest Airlines · Las Vegas to Detroit
- Flights
- 337
- Period
- July 2025 to June 2026
- Share of route
- 12%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on LAS to DTW sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 10 points worse than the national rate of 77.6%. The late ones land roughly 45 minutes behind schedule. That rests on 337 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 1,894 at 84.4% on time.
The national on-time rate over the same period is 77.6%, so Southwest on LAS to DTW runs 10 points behind the country as a whole. Across a thousand flights that is about 96 extra late arrivals.
Key figures
On time
68.0%
Arrivals under 15 minutes late, of 337 completed flights
Avg delay
44 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.81%
Whole route
81.7%
Every carrier on LAS to DTW, 2,838 flights
These figures cover 337 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.
Carrier by carrier
Southwest against every carrier on LAS to DTW
Southwest flew 337 of the 2,838 flights on LAS to DTW, about 12% of it. Its 68.0% on time is 14 points worse than the route as a whole, which runs 81.7%. Ranked by on-time rate it is last of four carriers on the route, where the range runs from Delta at 84.4% to Southwest at 68.0%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: 4 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 1,894 | 84.4% | 74 min | 0.53% | B+ |
| Frontier Airlinesthin sample | 44 | 84.1% | 47 min | 0.00% | B+ |
| Spirit Airlines | 563 | 80.7% | 88 min | 1.24% | B |
| Southwest Airlines (this page)thin sample | 337 | 68.0% | 44 min | 0.00% | C+ |
No carrier stands out. Delta tops the table at 84.4%, 4 points clear of the bottom, which is inside the range this kind of sample moves year to year.
Departure window
When Southwest runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 19 points, against 4 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am10 flights—
- 8am–11am21 flights—
- 11am–2pm275 flights64.4%
- 2pm–5pm30 flights83.3%
- 5pm–8pm1 flights—
- 8pm–5am—
Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 64.4% on time against 83.3% for 2pm–5pm. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 11am–2pm window is the busiest, with 275 flights scheduled in it.
Across the year
Southwest on LAS to DTW through the year
June is the worst month at 40.0% on time, 47 points below July, the best at 86.7%. 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. January was the busiest month here, with 31 flights.
Across the week, Tuesday is the strongest day at 79.5% on time and Friday the weakest at 51.0%. 29 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Southwest runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 4,746 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%Late-arriving aircraft
- 39%Carrier
- 17%National Airspace System
- 0%Extreme weather
44% 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 4,746 reported delay minutes here, that single category outweighs weather by 44 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 4,746 reported delay minutes.
The largest share of delay minutes, 39%, 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 1,867 of the 4,746 delay minutes reported here.
Cancellations are rare at 0.00%, below the national 1.81% and low enough to earn the plus on the grade. Almost no flights are called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
5.9% 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 roughly 45 minutes, which a normal layover absorbs.
At 1,749 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 runs 70.8% on time across 337 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 337 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.
What to do with this
Booking Southwest on LAS to DTW
Put together: treat all of this as provisional. 337 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 68.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 337 completed flights over 12 months sit behind that.
Related
Where to go next
- LAS to DTW, every carrier
- Southwest on DTW to LAS, the return leg
- Delta Air Lines on LAS to DTW84.4%
- Spirit Airlines on LAS to DTW80.7%
- Southwest Airlines network-wide record
- Harry Reid International (LAS) delay statistics
- Detroit Metropolitan Wayne County (DTW) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
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.