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DelayAtlas

Carrier route record

WNDCAATL

Southwest Airlines · Washington to Atlanta

Flights
1,139
Period
July 2025 to June 2026
Share of route
17%
Carriers
6
BGRADE

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

Southwest on DCA 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 an hour on average. That is a workable record, not a spotless one. That rests on 1,139 flights. The strongest carrier on the route with a full sample, Republic Airways, flew 461 at 81.3% on time.

Republic Airways is the most reliable of the three carriers covered here at 81.3% on time across 461 flights.

Key figures

On time

79.1%

Arrivals under 15 minutes late, of 1,114 completed flights

Avg delay

62 min

Across delayed arrivals only, not all flights

Cancelled

2.11%

National rate is 1.81%

Whole route

78.8%

Every carrier on DCA to ATL, 6,813 flights

These figures cover 1,139 flights between July 2025 and June 2026. The median arrival is 5 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 DCA to ATL

Southwest flew 1,139 of the 6,813 flights on DCA to ATL, about 17% of it. Its 79.1% on time is about level with the route as a whole at 78.8%. Ranked by on-time rate it is number four of six carriers on the route, where the range runs from Envoy at 82.4% to American at 67.8%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. Republic Airways arrives on time 81.3% of the time; PSA Airlines manages 68.8%. Sample sizes sit next to every figure, because a two-point gap across 1,055 flights means less than a ten-point one.

On-time performance by carrier on DCA to ATL
AirlineFlightsOn timeAvg delayCancelledGrade
Envoy Airthin sample25982.4%67 min1.54%B
Republic Airways46181.3%52 min3.69%B−
Delta Air Lines3,83880.9%88 min2.81%B
Southwest Airlines (this page)1,13979.1%62 min2.11%B
PSA Airlines1,05568.8%81 min8.25%C−
American Airlinesthin sample6167.8%102 min1.64%C

PSA Airlines cancels 8.3% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

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 13 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am353 flights91.6%
  • 8am–11am9 flights
  • 11am–2pm327 flights85.2%
  • 2pm–5pm256 flights70.4%
  • 5pm–8pm179 flights55.2%
  • 8pm–5am15 flights

Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 55.2% on time, against 91.6% 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 5am–8am window is the busiest, with 353 flights scheduled in it.

Across the year

Southwest on DCA to ATL through the year

On-time rate by calendar month96J91F82M77A71M74J64J77A84S80O83N76D
Darker means more delays. Figures are on-time percentages.January best, July worst

July is the worst month at 64.0% on time, 32 points below January, the best at 96.4%. 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 119 flights.

Across the week, Saturday is the strongest day at 86.9% on time and Sunday the weakest at 71.2%. 16 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week80.5Mon84.0Tue83.8Wed76.5Thu72.3Fri86.9Sat71.2Sun
Monday: 80.5 percent on time. Tuesday: 84.0 percent on time. Wednesday: 83.8 percent on time. Thursday: 76.5 percent on time. Friday: 72.3 percent on time. Saturday: 86.9 percent on time. Sunday: 71.2 percent on time

Delay causes

Why Southwest runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 49% of the 14,000 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.

  • Late-arriving aircraft
    49%
  • Carrier
    29%
  • National Airspace System
    19%
  • Extreme weather
    2%
  • Security
    1%

49% 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 14,000 reported delay minutes here, that single category outweighs weather by 23 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 14,483 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 91.6% on time here.

Cancellations sit at 2.11% against a national 1.81%, which is ordinary. Diversions add another 0.09%.

Connections and stage length

What a delay here costs

6.4% 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 an hour, which a normal layover absorbs.

The 547 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 73.5% on time across 1,139 flights, 6 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 6 points of difference.

The sample behind these figures is 1,139 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 DCA to ATL

Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 96.4% on time and July 64.0%, a swing of 32 points. If the dates move at all, move them out of July before you think about anything else. 1,114 completed flights over 12 months sit behind that.

Related

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.