Carrier route record
WNIND→DEN
Southwest Airlines · Indianapolis to Denver
- Flights
- 1,405
- Period
- July 2025 to June 2026
- Share of route
- 55%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on IND to DEN sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land about 50 minutes behind schedule. That rests on 1,405 flights, with a median arrival right on schedule.
The US average over the same twelve months is 77.6%, so there is little to separate Southwest on IND to DEN from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
75.2%
Arrivals under 15 minutes late, of 1,394 completed flights
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
0.50%
National rate is 1.81%
Whole route
77.3%
Every carrier on IND to DEN, 2,540 flights
These figures cover 1,405 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 IND to DEN
Southwest flew 1,405 of the 2,540 flights on IND to DEN, most of the route. Its 75.2% on time is 2 points worse than the route as a whole, which runs 77.3%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from United at 80.6% to Southwest at 75.2%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
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 |
|---|---|---|---|---|---|
| United Airlines | 841 | 80.6% | 68 min | 0.83% | B+ |
| Frontier Airlinesthin sample | 294 | 78.2% | 67 min | 0.34% | B+ |
| Southwest Airlines (this page) | 1,405 | 75.2% | 50 min | 0.50% | B+ |
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 36 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–8am364 flights93.0%
- 8am–11am159 flights89.3%
- 11am–2pm253 flights80.2%
- 2pm–5pm202 flights64.0%
- 5pm–8pm292 flights57.0%
- 8pm–5am135 flights57.1%
Scale runs 50% to 100%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 57.0% on time, against 93.0% 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 364 flights scheduled in it.
Across the year
Southwest on IND to DEN through the year
December is the weak month at 60.2% on time, against 82.3% in January. 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. July was the busiest month here, with 154 flights.
Across the week, Tuesday is the strongest day at 81.0% on time and Sunday the weakest at 72.6%. 8 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 47% of the 17,000 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.
- 47%Late-arriving aircraft
- 30%National Airspace System
- 21%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. That is a cascade, and cascades start small and grow through the day. Across 17,000 reported delay minutes here, that single category outweighs weather by 19 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 17,276 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 93.0% on time here.
Cancellations are rare at 0.50%, 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 costs
6.6% 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 50 minutes, which a normal layover absorbs.
The 976 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 70.6% on time across 1,409 flights, 5 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 5 points of difference.
The sample behind these figures is 1,405 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.
What to do with this
Booking Southwest on IND to DEN
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 82.3% on time and December 60.2%, a swing of 22 points. If the dates move at all, move them out of December before you think about anything else. 1,394 completed flights over 12 months sit behind that.
Related
Where to go next
- IND to DEN, every carrier
- Southwest on DEN to IND, the return leg
- United Airlines on IND to DEN80.6%
- Frontier Airlines on IND to DEN78.2%
- Southwest Airlines network-wide record
- Indianapolis International (IND) delay statistics
- Denver International (DEN) 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.