Flight WN4099
Southwest Airlines flight WN4099
Looking for WN4099 in the air…
Sacramento (SMF) to Portland (PDX)
Historically, this flight arrives 15+ minutes late 5% of the time, and when it is late the delay averages 23 minutes. It was cancelled 0.0% of the time.
- On-time arrivals
- 95.3%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 23 min
- Flights arriving 15+ minutes late
- Flights tracked
- 43
- 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).
Phoenix (PHX) to Ontario (ONT)
Historically, this flight arrives 15+ minutes late 14% of the time, and when it is late the delay averages 43 minutes. It was cancelled 0.0% of the time.
- On-time arrivals
- 85.7%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 43 min
- Flights arriving 15+ minutes late
- Flights tracked
- 42
- Scheduled flights in the period
What caused the delays
- Airline (crew, maintenance, cleaning) 70%
- Late-arriving aircraft 25%
- Air traffic control & airport 5%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Portland (PDX) to Denver (DEN)
Historically, this flight arrives 15+ minutes late 4% of the time, and when it is late the delay averages 68 minutes. It was cancelled 0.0% of the time.
- On-time arrivals
- 96.3%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 68 min
- Flights arriving 15+ minutes late
- Flights tracked
- 27
- Scheduled flights in the period
What caused the delays
- Airline (crew, maintenance, cleaning) 56%
- Late-arriving aircraft 44%
- Air traffic control & airport 0%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Ontario (ONT) to San Jose (SJC)
Historically, this flight arrives 15+ minutes late 40% of the time, and when it is late the delay averages 42 minutes. It was cancelled 0.0% of the time.
- On-time arrivals
- 60.0%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 42 min
- Flights arriving 15+ minutes late
- Flights tracked
- 25
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 95%
- Airline (crew, maintenance, cleaning) 5%
- Air traffic control & airport 0%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Nashville (BNA) to Orlando (MCO)
Only 18 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
- 91 min
- Flights arriving 15+ minutes late
- Flights tracked
- 18
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 64%
- Air traffic control & airport 32%
- Airline (crew, maintenance, cleaning) 4%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Kansas City (MCI) to Nashville (BNA)
Only 13 flights on record, which is too few for reliable odds.
- On-time arrivals
- 69.2%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 186 min
- Flights arriving 15+ minutes late
- Flights tracked
- 13
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 93%
- Airline (crew, maintenance, cleaning) 5%
- Air traffic control & airport 1%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Las Vegas (LAS) to Salt Lake City (SLC)
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
- 39 min
- Flights arriving 15+ minutes late
- Flights tracked
- 11
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 60%
- Airline (crew, maintenance, cleaning) 38%
- Air traffic control & airport 2%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Indianapolis (IND) to Baltimore (BWI)
Only 8 flights on record, which is too few for reliable odds.
- On-time arrivals
- 62.5%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 47 min
- Flights arriving 15+ minutes late
- Flights tracked
- 8
- Scheduled flights in the period
What caused the delays
- Air traffic control & airport 67%
- Late-arriving aircraft 20%
- Extreme weather 13%
- Airline (crew, maintenance, cleaning) 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
St Louis (STL) to Las Vegas (LAS)
Only 8 flights on record, which is too few for reliable odds.
- On-time arrivals
- 71.4%
- Less than 15 minutes late
- Cancelled
- 12.5%
- Of scheduled flights
- Average delay when late
- 100 min
- Flights arriving 15+ minutes late
- Flights tracked
- 8
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 93%
- Airline (crew, maintenance, cleaning) 5%
- Air traffic control & airport 2%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Baltimore (BWI) to Las Vegas (LAS)
Only 3 flights on record, which is too few for reliable odds.
- On-time arrivals
- 33.3%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 26 min
- Flights arriving 15+ minutes late
- Flights tracked
- 3
- Scheduled flights in the period
What caused the delays
- Airline (crew, maintenance, cleaning) 49%
- Late-arriving aircraft 45%
- Air traffic control & airport 6%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Tampa (TPA) to Baltimore (BWI)
Only 3 flights on record, which is too few for reliable odds.
- On-time arrivals
- 66.7%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 25 min
- Flights arriving 15+ minutes late
- Flights tracked
- 3
- Scheduled flights in the period
What caused the delays
- Airline (crew, maintenance, cleaning) 71%
- Air traffic control & airport 29%
- Late-arriving aircraft 0%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Las Vegas (LAS) to Kansas City (MCI)
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
Orlando (MCO) to Milwaukee (MKE)
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 | 60.0% | 25 |
| November 2025 | 85.7% | 28 |
| December 2025 | 68.4% | 38 |
| January 2026 | 57.1% | 7 |
| February 2026 | 63.6% | 23 |
| March 2026 | 50.0% | 2 |
| May 2026 | 100.0% | 2 |
| June 2026 | 93.5% | 31 |
| July 2026 | 97.3% | 37 |
| August 2026 | 70.0% | 10 |
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