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DelayAtlas

Carrier route record

WNDENBDL

Southwest Airlines · Denver to Hartford

Flights
194
Period
July 2025 to June 2026
Share of route
21%
Carriers
2
F−GRADE

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

Southwest on DEN to BDL earns an F−, which is as low as this site's scale goes for a reason. Only 52.9% of flights arrive inside the 15-minute window, 25 points worse than the national rate of 77.6%. Late arrivals average about an hour. Treat any tight connection here as a coin flip. That rests on 194 flights, with a median arrival 13 minutes late.

The national on-time rate over the same period is 77.6%, so Southwest on DEN to BDL runs 25 points behind the country as a whole. Across a thousand flights that is about 247 extra late arrivals.

Key figures

On time

52.9%

Arrivals under 15 minutes late, of 187 completed flights

Avg delay

55 min

Across delayed arrivals only, not all flights

Cancelled

3.61%

National rate is 1.81%

Whole route

74.9%

Every carrier on DEN to BDL, 922 flights

These figures cover 194 flights between July 2025 and June 2026. Beyond the headline rate, 13.4% 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 BDL

Southwest flew 194 of the 922 flights on DEN to BDL, about 21% of it. Its 52.9% on time is 22 points worse than the route as a whole, which runs 74.9%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from United at 80.6% to Southwest at 52.9%.

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 DEN to BDL
AirlineFlightsOn timeAvg delayCancelledGrade
United Airlines72880.6%60 min0.82%B+
Southwest Airlines (this page)thin sample19452.9%55 min3.61%F−

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 24 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–11am5 flights
  • 11am–2pm20 flights
  • 2pm–5pm33 flights70.0%
  • 5pm–8pm135 flights45.8%
  • 8pm–5am1 flights

Scale runs 35% to 75%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 45.8% on time, against 70.0% for the 2pm–5pm 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 5pm–8pm window is the busiest, with 135 flights scheduled in it.

Across the year

Southwest on DEN to BDL through the year

  • Jul–Sep 202592 flights42.7%
  • Oct–Dec 202568 flights57.4%
  • Jan–Mar 202634 flights73.3%

Scale runs 35% to 80%. 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 52.9% on time across 194 flights.

Southwest on DEN to BDL did not run the same all year. Its best quarter was Jan–Mar 2026 at 73.3% on time and its weakest Jul–Sep 2025 at 42.7%, a swing of 31 points on roughly 65 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.

Across the week, Saturday is the strongest day at 61.8% on time and Friday the weakest at 50.0%. 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 53% of the 4,859 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
    34%
  • National Airspace System
    11%
  • Extreme weather
    2%

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 4,859 reported delay minutes here, that single category outweighs weather by 29 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 4,859 reported delay minutes.

Cancellations run at 3.61%, against 1.81% nationally. That is about one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

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. 13.4% 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.

At 1,671 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

The return leg is a different operation and performs like one: it runs 80.0% on time across 194 flights, 27 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 27 points of difference.

One caution: this is a thin sample. 194 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 DEN to BDL

Put together: the delay figures matter less here than the 3.61% cancellation rate. A late arrival costs you about an hour; a cancelled flight costs you the day. Book the 2pm–5pm departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 187 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.