WN3865Southwest Airlines · STL → MDW
live · 1h ago
Route confirmed Southwest Airlines

WN3865 St LouisSTL · 20:45 ChicagoMDW · 21:55

WN3865 by Southwest Airlines flies from St Louis (STL) to Chicago (MDW) for the Wed, Sep 9 departure.

Right nowExpected in Chicago · today
21:55

arrival expected at MDW · on schedule

Typical gate push+44 minmedian posted departure
Typical arrival+25 minmedian over 4 operations
Wins back in air~19 minmedian gate push vs arrival · how planes make up time →

Where the minutes go

last 5 operations · gate push → arrival
0+30+60+90 min
09-09
+15 gate
09-08
+15 gate · −5 arrival
09-07
+51 gate · +26 arrival
09-04
+44 gate · +20 arrival
09-03
+25 arrival

The bar is how late it left the gate; the ring is where it actually arrived. Board clocks, not estimates.

The last 30 days

arrival outcome per operation

median arrival +25 min · 0 cancelled · 5 operations tracked

The route today

live boards
STLSt LouisOn-time likelySTL delay board →
MDWChicagoOn-time likelyMDW delay board →
STL→MDWevery carrier, schedules and on-time historyRoute intelligence →

Weather lens

Delay & cancellation outlook for this flight

Measured, 90-day sample
44%Chance of 15+ min delay
1.3%Chance of cancellation
+11 minAvg hub delay right now

Conditions at STL and MDW are near their clear-air norm right now, so this reflects the route's recent baseline rather than a weather penalty. For this route and airline, under conditions like today's, over the last 90 days.

Pro Flight Search tracking, 90 days · the weather × delay correlation study → · live weather risk by airport →

When it flies

scheduled departures
061422
M
T
W
T
F
S
S

Each mark is a scheduled departure at its origin-local time. Today is highlighted.

Other St Louis to Chicago flights today

same route · Southwest Airlines
WN2052departs 06:05
WN3861departs 06:30
WN4752departs 06:45
WN2742departs 10:35
WN3862departs 10:45
WN3864departs 15:45

If WN3865 is cancelled, these are the other Southwest Airlines nonstop flights from St Louis to Chicago on the same day, with scheduled departure times in STL local time. Most flights posting a delay still operate — rebooking usually only beats a very large posted delay. Every airline on this route →

How WN3865 actually runs

Pro Flight Search has tracked every published board update for WN3865 across the STL and MDW boards: schedule changes, gate pushes and actual clocks. Usually lands ~25 min late. Based on 4 confirmed landings · 1/4 within 15 min of schedule. Pushes back late but makes up time in the air.

The verdict above is that record speaking, so it reflects how WN3865 operates rather than what the timetable promises. Numbers refresh as new flights operate.

Technical record

How this operation is measured

board clocksaircraft

Board log

scheduled → actual, per operation
09-09STL 20:45 21:00 (+15)MDW 21:55
09-08STL 20:45 21:00 (+15)MDW 21:55 21:50 (−5)
09-07STL 20:50 21:41 (+51)MDW 22:00 22:26 (+26)
09-04STL 20:50 21:34 (+44)MDW 22:00 22:20 (+20)
09-03STL MDW 22:00 22:25 (+25)

Aircraft

Recent tails: N8964L, N8819L, N1805U.

Board clocks recorded as STL and MDW published them.

Cite this data

Journalists, bloggers, and researchers may cite this page with attribution and a link to Pro Flight Search.

Suggested citation

Pro Flight Search — WN3865 St Louis to Chicago on-time performance, measured from the STL and MDW airport boards.

Canonical URL
https://proflightsearch.com/flight/WN3865
How we measure this →