Carrier route record
WNDEN→IND
Southwest Airlines · Denver to Indianapolis
- Flights
- 1,409
- 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 DEN to IND sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 1,409 flights, with a median arrival 1 minute late.
The national on-time rate over the same period is 77.6%, so Southwest on DEN to IND runs 7 points behind the country as a whole. Across a thousand flights that is about 70 extra late arrivals.
Key figures
On time
70.6%
Arrivals under 15 minutes late, of 1,401 completed flights
Avg delay
58 min
Across delayed arrivals only, not all flights
Cancelled
0.57%
National rate is 1.81%
Whole route
75.5%
Every carrier on DEN to IND, 2,544 flights
These figures cover 1,409 flights between July 2025 and June 2026. Beyond the headline rate, 9.3% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Southwest against every carrier on DEN to IND
Southwest flew 1,409 of the 2,544 flights on DEN to IND, most of the route. Its 70.6% on time is 5 points worse than the route as a whole, which runs 75.5%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from United at 81.6% to Southwest at 70.6%. 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 | 81.6% | 57 min | 0.36% | B+ |
| Frontier Airlinesthin sample | 294 | 81.6% | 59 min | 0.00% | B+ |
| Southwest Airlines (this page) | 1,409 | 70.6% | 58 min | 0.57% | C+ |
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 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–8am111 flights94.6%
- 8am–11am339 flights86.1%
- 11am–2pm291 flights71.5%
- 2pm–5pm251 flights65.9%
- 5pm–8pm285 flights54.6%
- 8pm–5am132 flights51.5%
Scale runs 45% to 100%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 51.5% on time, against 94.6% 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 8am–11am window is the busiest, with 339 flights scheduled in it.
Across the year
Southwest on DEN to IND through the year
August is the worst month at 48.7% on time, 36 points below January, the best at 84.7%. 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. July was the busiest month here, with 154 flights.
Across the week, Saturday is the strongest day at 77.4% on time and Monday the weakest at 65.9%. 12 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 54% of the 24,000 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.
- 54%Late-arriving aircraft
- 32%Carrier
- 14%National Airspace System
- 1%Extreme weather
54% 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 24,000 reported delay minutes here, that single category outweighs weather by 54 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 24,076 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 94.6% on time here.
Cancellations are rare at 0.57%, 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
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.3% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
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 75.2% on time across 1,405 flights, 5 points above 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 1,409 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 DEN to IND
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 84.7% on time and August 48.7%, a swing of 36 points. If the dates move at all, move them out of August before you think about anything else. 1,401 completed flights over 12 months sit behind that.
Related
Where to go next
- DEN to IND, every carrier
- Southwest on IND to DEN, the return leg
- United Airlines on DEN to IND81.6%
- Frontier Airlines on DEN to IND81.6%
- Southwest Airlines network-wide record
- Denver International (DEN) delay statistics
- Indianapolis International (IND) 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.