Carrier route record

WNIND→MIA

Southwest Airlines · Indianapolis to Miami

Flights: 113
Period: July 2025 to June 2026
Share of route: 12%
Carriers: 6

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.

Southwest on IND to MIA sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land about 45 minutes behind schedule. That rests on 113 flights, with a median arrival 2 minutes late.

The US average over the same twelve months is 77.6%, so there is little to separate Southwest on IND to MIA from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

74.3%

Arrivals under 15 minutes late, of 113 completed flights

Avg delay

46 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.81%

Whole route

78.9%

Every carrier on IND to MIA, 928 flights

These figures cover 113 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 MIA

Southwest flew 113 of the 928 flights on IND to MIA, about 12% of it. Its 74.3% on time is 5 points worse than the route as a whole, which runs 78.9%. Ranked by on-time rate it is number three of six carriers on the route, where the range runs from American at 80.3% to Republic at 50.0%. Four 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.

On-time performance by carrier on IND to MIA
Airline	Flights	On time	Avg delay	Cancelled	Grade
American Airlines	749	80.3%	104 min	1.20%	B
Frontier Airlinesthin sample	4	75.0%	86 min	0.00%	B+
Southwest Airlines (this page)thin sample	113	74.3%	46 min	0.00%	C+
Envoy Airthin sample	56	73.2%	72 min	0.00%	C+
Delta Air Linesthin sample	2	50.0%	22 min	0.00%	F+
Republic Airwaysthin sample	4	50.0%	31 min	0.00%	F+

Departure window

When Southwest runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 113 flights.

5am–8am—
8am–11am15 flights—
11am–2pm66 flights74.2%
2pm–5pm32 flights75.0%
5pm–8pm—
8pm–5am—

Scale runs 65% to 80%. Rows with fewer than 30 flights show a dash.

The 2pm–5pm window is the strongest at 75.0% on time. The full set of windows spans about a point.

Across the year

Southwest on IND to MIA through the year

Jan–Mar 202664 flights67.2%
Apr–Jun 202649 flights83.7%

Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 74.3% on time across 113 flights.

Split by quarter, Southwest on IND to MIA logged 64 flights in Jan–Mar 2026 and 49 flights in Apr–Jun 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 74.3% annual figure is the one to use.

Delay causes

Why Southwest runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 46% of the 1,325 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.

Late-arriving aircraft
46%
National Airspace System
36%
Carrier
18%
Security
0%

46% 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 1,325 reported delay minutes here, that single category outweighs weather by 46 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 1,325 reported delay minutes.

36% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 478 minutes out of 1,325, against a national NAS share of 21%.

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

5.3% 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 45 minutes, which a normal layover absorbs.

The 1,020 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 56.1% on time across 115 flights, 18 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 18 points of difference.

One caution: this is a thin sample. 113 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 IND to MIA

Put together: treat all of this as provisional. 113 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 74.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 113 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures