ON TIMEBOARD

WN 40 on time

Southwest Airlines 40: Houston to Dallas at 4:00 p.m. (past 12 months)

On time
69%
198 flights · likely 62–75%
Cancelled
0.5%
of scheduled flights
Typical arrival
−3 min
median vs schedule
When late
+55 min
average delay
Similar flights
74%
WN, same route & hour

About 1 in 3 WN 40 flights from Houston arrived 15+ minutes late, diverted or cancelled over the past year (31%); 0.5% were cancelled. The typical flight landed 3 minutes early.

WN 40: HOU → DAL

Scheduled to leave Houston at 4:00 p.m. local time. Over the past year it arrived on time 69% of the time (198 flights), worse than other WN flights on the route at that hour (74%). Last seen in the data Aug 31, 2026.

Month by month

40%70%100%Sep 2025: 83% on time (23 flights)83SepOct 2025: 72% on time (18 flights)72OctNov 2025: 80% on time (15 flights)80NovDec 2025: too few flights (13 flights)DecJan 2026: too few flights (8 flights)JanFeb 2026: 80% on time (15 flights)80FebMar 2026: 62% on time (21 flights)62MarApr 2026: 59% on time (17 flights)59AprMay 2026: 68% on time (19 flights)68MayJun 2026: 47% on time (17 flights)47JunJul 2026: 61% on time (18 flights)61JulAug 2026: too few flights (14 flights)Aug

By day of week

DayFlightsOn time
Monday4670%
Tuesday13—
Wednesday10—
Thursday4367%
Friday4777%
Saturday14—
Sunday2556%

Why it was late

Late inbound plane 51%Air traffic & airport (NAS) 32%Airline (crew, maintenance, ops) 16%Severe weather 2%

All flights HOU → DAL · Connecting off WN 40? Check the risk

Questions

How often is WN 40 from HOU to DAL late?

Southwest Airlines 40 from Houston, TX to Dallas, TX arrived 15 or more minutes late, was diverted or was cancelled on 31% of 198 scheduled flights between September 2025 and August 2026. 0.5% were cancelled.

Flight numbers change. Figures cover flights with this airline, number and route only. "Likely range" is the 95% interval for the true on-time rate given the number of flights. This is history, not live status: check Southwest Airlines for today's flight. Method.