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Flight UA1639

United Airlines flight UA1639

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  • Advisory Coastal Flood Advisory OAK, SFO, SQL, STS

    COASTAL FLOOD ADVISORY REMAINS IN EFFECT UNTIL 1 PM PST MONDAY

    Weather

Denver (DEN) to St Louis (STL)

Historically, this flight arrives 15+ minutes late 18% of the time, and when it is late the delay averages 103 minutes. It was cancelled 0.0% of the time.

On-time arrivals
82.4%
Less than 15 minutes late
Cancelled
0.0%
Of scheduled flights
Average delay when late
103 min
Flights arriving 15+ minutes late
Flights tracked
102
Scheduled flights in the period

What caused the delays

  • Airline (crew, maintenance, cleaning) 40%
  • Late-arriving aircraft 39%
  • Air traffic control & airport 20%
  • Extreme weather 0%
  • Security 0%

Share of delay minutes airlines attributed to each cause (BTS).

St Louis (STL) to Chicago (ORD)

Historically, this flight arrives 15+ minutes late 36% of the time, and when it is late the delay averages 123 minutes. It was cancelled 4.9% of the time.

On-time arrivals
64.1%
Less than 15 minutes late
Cancelled
4.9%
Of scheduled flights
Average delay when late
123 min
Flights arriving 15+ minutes late
Flights tracked
82
Scheduled flights in the period

What caused the delays

  • Air traffic control & airport 47%
  • Airline (crew, maintenance, cleaning) 39%
  • Late-arriving aircraft 14%
  • Extreme weather 0%
  • Security 0%

Share of delay minutes airlines attributed to each cause (BTS).

San Francisco (SFO) to Redmond (RDM)

Historically, this flight arrives 15+ minutes late 11% of the time, and when it is late the delay averages 39 minutes. It was cancelled 0.0% of the time.

On-time arrivals
89.1%
Less than 15 minutes late
Cancelled
0.0%
Of scheduled flights
Average delay when late
39 min
Flights arriving 15+ minutes late
Flights tracked
55
Scheduled flights in the period

What caused the delays

  • Air traffic control & airport 70%
  • Airline (crew, maintenance, cleaning) 21%
  • Late-arriving aircraft 9%
  • Extreme weather 0%
  • Security 0%

Share of delay minutes airlines attributed to each cause (BTS).

Miami (MIA) to Chicago (ORD)

Historically, this flight arrives 15+ minutes late 57% of the time, and when it is late the delay averages 62 minutes. It was cancelled 3.8% of the time.

On-time arrivals
43.1%
Less than 15 minutes late
Cancelled
3.8%
Of scheduled flights
Average delay when late
62 min
Flights arriving 15+ minutes late
Flights tracked
53
Scheduled flights in the period

What caused the delays

  • Air traffic control & airport 51%
  • Late-arriving aircraft 40%
  • Airline (crew, maintenance, cleaning) 10%
  • Extreme weather 0%
  • Security 0%

Share of delay minutes airlines attributed to each cause (BTS).

San Luis Obispo (SBP) to San Francisco (SFO)

Historically, this flight arrives 15+ minutes late 23% of the time, and when it is late the delay averages 125 minutes. It was cancelled 0.0% of the time.

On-time arrivals
77.4%
Less than 15 minutes late
Cancelled
0.0%
Of scheduled flights
Average delay when late
125 min
Flights arriving 15+ minutes late
Flights tracked
53
Scheduled flights in the period

What caused the delays

  • Airline (crew, maintenance, cleaning) 92%
  • Air traffic control & airport 8%
  • Late-arriving aircraft 0%
  • Extreme weather 0%
  • Security 0%

Share of delay minutes airlines attributed to each cause (BTS).

San Francisco (SFO) to New Orleans (MSY)

Historically, this flight arrives 15+ minutes late 9% of the time, and when it is late the delay averages 33 minutes. It was cancelled 0.0% of the time.

On-time arrivals
91.4%
Less than 15 minutes late
Cancelled
0.0%
Of scheduled flights
Average delay when late
33 min
Flights arriving 15+ minutes late
Flights tracked
35
Scheduled flights in the period

What caused the delays

  • Air traffic control & airport 56%
  • Late-arriving aircraft 44%
  • Airline (crew, maintenance, cleaning) 0%
  • Extreme weather 0%
  • Security 0%

Share of delay minutes airlines attributed to each cause (BTS).

San Francisco (SFO) to Austin (AUS)

Historically, this flight arrives 15+ minutes late 38% of the time, and when it is late the delay averages 54 minutes. It was cancelled 0.0% of the time.

On-time arrivals
61.9%
Less than 15 minutes late
Cancelled
0.0%
Of scheduled flights
Average delay when late
54 min
Flights arriving 15+ minutes late
Flights tracked
21
Scheduled flights in the period

What caused the delays

  • Air traffic control & airport 46%
  • Airline (crew, maintenance, cleaning) 35%
  • Late-arriving aircraft 19%
  • Extreme weather 0%
  • Security 0%

Share of delay minutes airlines attributed to each cause (BTS).

Fort Myers (RSW) to Chicago (ORD)

Only 17 flights on record, which is too few for reliable odds.

On-time arrivals
82.4%
Less than 15 minutes late
Cancelled
0.0%
Of scheduled flights
Average delay when late
47 min
Flights arriving 15+ minutes late
Flights tracked
17
Scheduled flights in the period

What caused the delays

  • Late-arriving aircraft 65%
  • Air traffic control & airport 35%
  • Airline (crew, maintenance, cleaning) 0%
  • Extreme weather 0%
  • Security 0%

Share of delay minutes airlines attributed to each cause (BTS).

Chicago (ORD) to Dulles (IAD)

Only 6 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
47 min
Flights arriving 15+ minutes late
Flights tracked
6
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).

Houston (IAH) to Nashville (BNA)

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

In the news

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On-time arrivals by month
Sep 2025 Aug 2026
Show as table
MonthOn timeFlights
September 2025 86.7% 30
October 2025 93.5% 31
November 2025 89.7% 29
December 2025 74.1% 27
January 2026 75.0% 16
February 2026 28.6% 14
March 2026 33.3% 23
April 2026 87.1% 31
May 2026 69.4% 62
June 2026 81.4% 60
July 2026 69.0% 61
August 2026 68.3% 41

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

Latest airport & airline headlines

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Headlines found by Google News; stories open on the publisher's site.