Carrier route record

WNMIA→IND

Southwest Airlines · Miami to Indianapolis

Flights: 115
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 MIA to IND earns a D+, which is as low as this site's scale goes for a reason. Only 56.1% of flights arrive inside the 15-minute window, 21 points worse than the national rate of 77.6%. Late arrivals average roughly 55 minutes. Treat any tight connection here as a coin flip. That rests on 115 flights, with a median arrival 12 minutes late.

The national on-time rate over the same period is 77.6%, so Southwest on MIA to IND runs 21 points behind the country as a whole. Across a thousand flights that is about 215 extra late arrivals.

On time

56.1%

Arrivals under 15 minutes late, of 114 completed flights

Avg delay

54 min

Across delayed arrivals only, not all flights

Cancelled

0.87%

National rate is 1.81%

Whole route

73.0%

Every carrier on MIA to IND, 931 flights

These figures cover 115 flights between July 2025 and June 2026. Beyond the headline rate, 13.2% 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 MIA to IND

Southwest flew 115 of the 931 flights on MIA to IND, about 12% of it. Its 56.1% on time is 17 points worse than the route as a whole, which runs 73.0%. Ranked by on-time rate it is last of six carriers on the route, where the range runs from Delta at 100.0% to Southwest at 56.1%. 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 MIA to IND
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Linesthin sample	2	100.0%	—	0.00%	A+
Republic Airwaysthin sample	4	100.0%	—	0.00%	A+
Envoy Airthin sample	56	87.5%	84 min	0.00%	A+
Frontier Airlinesthin sample	4	75.0%	17 min	0.00%	B+
American Airlines	750	74.2%	70 min	1.20%	C
Southwest Airlines (this page)thin sample	115	56.1%	54 min	0.87%	D+

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 115 flights.

There are not enough flights in each departure window to split Southwest's MIA to IND record by time of day without the percentages moving on noise. The headline rate of 56.1% is the reliable figure here.

Across the year

Southwest on MIA to IND through the year

Jan–Mar 202666 flights56.9%
Apr–Jun 202649 flights55.1%

Scale runs 45% to 60%. 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 56.1% on time across 115 flights.

Split by quarter, Southwest on MIA to IND logged 66 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 56.1% 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 51% of the 2,679 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
51%
Carrier
28%
National Airspace System
14%
Extreme weather
7%

51% 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 2,679 reported delay minutes here, that single category outweighs weather by 7 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 2,679 reported delay minutes.

Cancellations are rare at 0.87%, 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. 13.2% 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 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 74.3% on time across 113 flights, 18 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 18 points of difference.

One caution: this is a thin sample. 115 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 MIA to IND

Put together: treat all of this as provisional. 115 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 56.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 114 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