Carrier route record

WNIND→ATL

Southwest Airlines · Indianapolis to Atlanta

Flights: 328
Period: July 2025 to June 2026
Share of route: 10%
Carriers: 5

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

Southwest on IND to ATL lands a B+, 2 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 50 minutes on average. That is a workable record, not a spotless one. That rests on 328 flights, with a median arrival 3 minutes early.

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

On time

79.5%

Arrivals under 15 minutes late, of 327 completed flights

Avg delay

51 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.81%

Whole route

88.5%

Every carrier on IND to ATL, 3,187 flights

These figures cover 328 flights between July 2025 and June 2026. The median arrival is 3 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.

Carrier by carrier

Southwest against every carrier on IND to ATL

Southwest flew 328 of the 3,187 flights on IND to ATL, about 10% of it. Its 79.5% on time is 9 points worse than the route as a whole, which runs 88.5%. Ranked by on-time rate it is number three of five carriers on the route, where the range runs from American at 100.0% to Frontier at 65.2%. Three 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 ATL
Airline	Flights	On time	Avg delay	Cancelled	Grade
American Airlinesthin sample	1	100.0%	—	0.00%	A+
Delta Air Lines	2,710	90.8%	78 min	1.44%	A
Southwest Airlines (this page)thin sample	328	79.5%	51 min	0.00%	B+
Spirit Airlinesthin sample	7	71.4%	169 min	0.00%	C+
Frontier Airlinesthin sample	141	65.2%	71 min	2.13%	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 22 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–8am—
8am–11am36 flights97.2%
11am–2pm139 flights82.6%
2pm–5pm135 flights75.6%
5pm–8pm18 flights—
8pm–5am—

Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 97.2% of the time, against 75.6% for the afternoon window. That is 22 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 139 flights scheduled in it.

Across the year

Southwest on IND to ATL through the year

Jul–Sep 202592 flights76.9%
Oct–Dec 202592 flights82.6%
Jan–Mar 202685 flights78.8%
Apr–Jun 202659 flights79.7%

Scale runs 70% 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 79.5% on time across 328 flights.

Quarter by quarter Southwest on IND to ATL held fairly steady: 76.9% in Jul–Sep 2025, 82.6% in Oct–Dec 2025, 78.8% in Jan–Mar 2026 and 79.7% in Apr–Jun 2026. A spread of 6 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Across the week, Wednesday is the strongest day at 92.3% on time and Saturday the weakest at 69.0%. 23 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 53% of the 3,381 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
53%
Carrier
24%
National Airspace System
22%
Extreme weather
1%

53% 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 3,381 reported delay minutes here, that single category outweighs weather by 42 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 3,381 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 97.2% on time 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

Badly late arrivals are rare here: only 4.6% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

At 432 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 8am–11am window matters as much as it does.

The return leg runs 79.5% on time across 330 flights, within half a point 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. 328 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 ATL

Put together: treat all of this as provisional. 328 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 79.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 327 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