Southwest vs United: On-Time Performance Compared

Last 12 months · Aug 2025 – Jul 2026

Data through July 2026 · Last updated October 18, 2026

Over the last 12 months 79.3% of United flights arrived on time, compared with 76.4% for Southwest.

Southwest cancelled fewer flights (0.9% vs 1.0%), and late flights averaged 53 minutes late on Southwest vs 71 on United.

On the 198 routes both airlines fly regularly, Southwest had the better on-time record on 14 and United on 184.

Southwest vs United: key numbers

Last 12 months, all flights each airline operated.

SouthwestUnited

On-time arrivals76.4%79.3%

On-time departures71.8%81.4%

Cancelled0.9%1.0%

Diverted0.2%0.3%

On-time arrival % each month, last 24 months.

SouthwestUnited

60%70%80%90%

Aug ’24Nov ’24Feb ’25May ’25Aug ’25Nov ’25Feb ’26May ’26

Share of each airline’s reported delay minutes by cause, last 12 months.

SouthwestUnited

Airline (carrier)28.4%25.6%

Weather2.3%4.2%

Air traffic system (NAS)17.9%34.0%

Security0.3%0.0%

Late-arriving aircraft51.1%36.2%

198 routes where each airline had at least 100 completed flights in the last 12 months; the 25 busiest are shown. Better on-time rate in bold.

Route	Southwest on time	United on time	Southwest flights	United flights
DEN → PHX	72.3%	81.5%	3,964	2,362
PHX → DEN	72.7%	83.9%	3,937	2,363
DEN → LAS	72.4%	79.6%	3,143	2,392
LAS → DEN	71.0%	84.4%	3,119	2,388
LAX → DEN	73.3%	87.8%	1,902	3,079
DEN → LAX	68.5%	84.3%	1,903	3,077
DEN → SFO	50.9%	70.1%	1,415	3,412
SFO → DEN	60.1%	82.5%	1,413	3,410
SFO → LAX	59.8%	78.5%	1,425	3,297
LAX → SFO	53.9%	64.4%	1,426	3,291
SAN → SFO	55.4%	69.0%	2,001	2,633
SFO → SAN	50.5%	74.9%	2,001	2,633
DEN → SAN	69.2%	79.5%	2,388	2,074
SAN → DEN	72.0%	86.1%	2,386	2,074
AUS → DEN	73.2%	84.6%	2,385	1,899
DEN → AUS	75.0%	80.0%	2,362	1,898
ORD → DEN	74.4%	78.9%	390	3,816
DEN → ORD	67.5%	72.3%	389	3,815
SFO → LAS	64.0%	78.6%	1,314	2,793
LAS → SFO	46.2%	65.1%	1,312	2,793
LAS → LAX	68.9%	86.2%	2,382	1,572
LAX → LAS	71.2%	84.0%	2,377	1,570
MCO → DEN	73.2%	86.5%	1,928	1,740
DEN → MCO	74.7%	82.7%	1,923	1,744
DEN → SMF	65.9%	81.3%	1,873	1,793