Flight WN4639
Southwest Airlines flight WN4639
Looking for WN4639 in the air…
Alerts at this flight's airports
Houston (HOU) to Denver (DEN)
Historically, this flight arrives 15+ minutes late 28% of the time, and when it is late the delay averages 64 minutes. It was cancelled 0.0% of the time.
- On-time arrivals
- 71.7%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 64 min
- Flights arriving 15+ minutes late
- Flights tracked
- 60
- Scheduled flights in the period
What caused the delays
- Air traffic control & airport 51%
- Airline (crew, maintenance, cleaning) 33%
- Late-arriving aircraft 16%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Pittsburgh (PIT) to St Louis (STL)
Historically, this flight arrives 15+ minutes late 3% of the time, and when it is late the delay averages 74 minutes. It was cancelled 0.0% of the time.
- On-time arrivals
- 96.6%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 74 min
- Flights arriving 15+ minutes late
- Flights tracked
- 58
- Scheduled flights in the period
What caused the delays
- Airline (crew, maintenance, cleaning) 75%
- Air traffic control & airport 25%
- Late-arriving aircraft 0%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Las Vegas (LAS) to San Jose (SJC)
Historically, this flight arrives 15+ minutes late 23% of the time, and when it is late the delay averages 75 minutes. It was cancelled 0.0% of the time.
- On-time arrivals
- 77.3%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 75 min
- Flights arriving 15+ minutes late
- Flights tracked
- 22
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 70%
- Airline (crew, maintenance, cleaning) 26%
- Air traffic control & airport 4%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Palm Springs (PSP) to Las Vegas (LAS)
Only 11 flights on record, which is too few for reliable odds.
- On-time arrivals
- 72.7%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 67 min
- Flights arriving 15+ minutes late
- Flights tracked
- 11
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 99%
- Airline (crew, maintenance, cleaning) 1%
- Air traffic control & airport 0%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Sacramento (SMF) to Palm Springs (PSP)
Only 11 flights on record, which is too few for reliable odds.
- On-time arrivals
- 63.6%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 61 min
- Flights arriving 15+ minutes late
- Flights tracked
- 11
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 92%
- Airline (crew, maintenance, cleaning) 8%
- Air traffic control & airport 0%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Phoenix (PHX) to Spokane (GEG)
Only 10 flights on record, which is too few for reliable odds.
- On-time arrivals
- 90.0%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 34 min
- Flights arriving 15+ minutes late
- Flights tracked
- 10
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 44%
- Air traffic control & airport 44%
- Airline (crew, maintenance, cleaning) 12%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Denver (DEN) to Sacramento (SMF)
Only 8 flights on record, which is too few for reliable odds.
- On-time arrivals
- 50.0%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 61 min
- Flights arriving 15+ minutes late
- Flights tracked
- 8
- Scheduled flights in the period
What caused the delays
- Airline (crew, maintenance, cleaning) 77%
- Late-arriving aircraft 14%
- Air traffic control & airport 9%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Pensacola (PNS) to Nashville (BNA)
Only 8 flights on record, which is too few for reliable odds.
- On-time arrivals
- 100.0%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- —
- Flights arriving 15+ minutes late
- Flights tracked
- 8
- Scheduled flights in the period
Boise (BOI) to Oakland (OAK)
Only 5 flights on record, which is too few for reliable odds.
- On-time arrivals
- 80.0%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 155 min
- Flights arriving 15+ minutes late
- Flights tracked
- 5
- Scheduled flights in the period
What caused the delays
- Airline (crew, maintenance, cleaning) 100%
- Late-arriving aircraft 0%
- Air traffic control & airport 0%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Washington (DCA) to Houston (HOU)
Only 4 flights on record, which is too few for reliable odds.
- On-time arrivals
- 33.3%
- Less than 15 minutes late
- Cancelled
- 25.0%
- Of scheduled flights
- Average delay when late
- 87 min
- Flights arriving 15+ minutes late
- Flights tracked
- 4
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 55%
- Extreme weather 39%
- Airline (crew, maintenance, cleaning) 6%
- Air traffic control & airport 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Kansas City (MCI) to Portland (PDX)
Only 4 flights on record, which is too few for reliable odds.
- On-time arrivals
- 25.0%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 35 min
- Flights arriving 15+ minutes late
- Flights tracked
- 4
- Scheduled flights in the period
What caused the delays
- Airline (crew, maintenance, cleaning) 58%
- Late-arriving aircraft 42%
- Air traffic control & airport 0%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Salt Lake City (SLC) to Denver (DEN)
Only 1 flight on record, which is too few for reliable odds.
- On-time arrivals
- 100.0%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- —
- Flights arriving 15+ minutes late
- Flights tracked
- 1
- Scheduled flights in the period
Show as table
| Month | On time | Flights |
|---|---|---|
| October 2025 | 100.0% | 8 |
| November 2025 | 100.0% | 3 |
| December 2025 | 50.0% | 2 |
| January 2026 | 100.0% | 6 |
| February 2026 | 61.9% | 42 |
| March 2026 | 92.3% | 13 |
| April 2026 | 100.0% | 26 |
| May 2026 | 96.8% | 31 |
| June 2026 | 70.0% | 30 |
| July 2026 | 70.0% | 30 |
| August 2026 | 50.0% | 11 |
Source: U.S. DOT Bureau of Transportation Statistics on-time data, September 2025 – August 2026. Covers flights operated by reporting U.S. carriers. About our data