Route Reliability

Route reliability

Houston (IAH) to San Francisco (SFO): which airline is most on time?

On-time arrivals, cancellations and long delays for every airline that reported nonstop flights from Houston, TX (IAH) to San Francisco, CA (SFO), September 2025 to August 2026.

Historical performance Official DOT data through August 2026 · Not live flight status

Houston, TXSan Francisco, CA

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Three-letter airport codes, nonstop U.S. domestic flights. One direction at a time.

Route at a glance · September 2025 to August 2026

IAH to SFO

Houston, TX to San Francisco, CA

On time
77.8%vs 75.6% U.S. average Better than average
Cancelled
0.4%vs 1.9% U.S. average Better than average
60+ min late
7.0%vs 8.1% U.S. average Better than average
Scheduled flights
3,578in 12 months1 airline
Only rated airline
United Airlines77.8% on time · 3,578 flights

On time more often than the U.S. average, with fewer cancellations.

Compared with all U.S. flights, September 2025 to August 2026. “About average” means within 1.5 points for on time, 0.3 for cancelled and 1 for 60+ minutes late.

Airlines on this route

Ranked by on-time arrival

Airlines from IAH to SFO, September 2025 to August 2026. Rates are shares of all scheduled flights.
Airline On time Cancelled 60+ min late Avg delay when late Diverted Flights
1. United Airlines 77.8% 0.4% 7.0% 62 min 0.1% 3,578

On time = arrived within 15 minutes of schedule. Avg delay when late = average arrival delay of flights 15+ minutes late. "Most reliable" needs at least 300 flights in 12 months. Tap a heading to sort.

What this means

How IAH to SFO compares.

  • United Airlines was the only airline with enough flights on this route to rate (3,578 flights). 77.8% of them arrived within 15 minutes of schedule.
  • 0.4% of flights on this route were cancelled, 1.5 points lower than the U.S. average of 1.9%.
  • 7.0% of flights, about 1 in 14, arrived an hour or more late. When a flight was late (15+ minutes), the average arrival delay was 62 min.
  • Overall, 77.8% of flights on this route arrived on time, 2.2 points higher than the U.S. average of 75.6%.
  • Over the last 3 years, September was the most reliable month on this route (85.8% on time) and June the least reliable (63.8%).
  • Cancellations peaked in January, when 5.7% of flights were cancelled.
  • Flights scheduled to depart before 6 am were the most punctual (96.8% on time); flights scheduled to depart 7 pm to 8 pm were the least (51.8%).
  • In the other direction, San Francisco (SFO) to Houston (IAH), 83.6% of flights were on time and 0.3% were cancelled. Compare airlines SFO to IAH.

Best and worst months to fly IAH to SFO

Jan 74.9%
Feb 79.1%
Mar 78.0%
Apr 74.0%
May 67.1%
Jun 63.8%
Jul 68.0%
Aug 83.0%
Sep 85.8%
Oct 83.4%
Nov 80.9%
Dec 78.2%
Share of scheduled flights on time 12-month average 77.8%
All airlines combined, by calendar month, September 2023 to August 2026 (3 years pooled). Scale starts at zero.
Show as table
PeriodOn timeFlights
January 74.9% 792
February 79.1% 736
March 78.0% 842
April 74.0% 832
May 67.1% 868
June 63.8% 865
July 68.0% 875
August 83.0% 858
September 85.8% 825
October 83.4% 862
November 80.9% 824
December 78.2% 872

Month by month, last 12 months

Sep 89.3%
Oct 81.7%
Nov 81.6%
Dec 79.4%
Jan 83.5%
Feb 85.2%
Mar 87.1%
Apr 74.0%
May 66.4%
Jun 57.0%
Jul 68.0%
Aug 81.4%
Share of scheduled flights on time U.S. average 75.6%
All airlines combined, September 2025 to August 2026. Scale starts at zero.
Show as table
PeriodOn timeFlights
Sep 2025 89.3% 289
Oct 2025 81.7% 306
Nov 2025 81.6% 299
Dec 2025 79.4% 311
Jan 2026 83.5% 303
Feb 2026 85.2% 277
Mar 2026 87.1% 310
Apr 2026 74.0% 300
May 2026 66.4% 307
Jun 2026 57.0% 300
Jul 2026 68.0% 297
Aug 2026 81.4% 279

Best and worst departure times

<6a 96.8%
6a Insufficient sample
7a 88.2%
8a 72.4%
9a 71.6%
10a 70.7%
11a Insufficient sample
12p 77.7%
1p Insufficient sample
2p 84.1%
3p 77.4%
4p 78.5%
5p 86.8%
6p 64.5%
7p 51.8%
8p 65.2%
9p 80.7%
10p Insufficient sample
11p Insufficient sample
Share of scheduled flights on time
By scheduled local departure hour at IAH, September 2025 to August 2026. Hours with no scheduled flights are omitted. Scale starts at zero.
Show as table
PeriodOn timeFlights
Departing before 6 am 96.8% 343
Departing 6 am to 7 am Insufficient sample 1
Departing 7 am to 8 am 88.2% 365
Departing 8 am to 9 am 72.4% 156
Departing 9 am to 10 am 71.6% 201
Departing 10 am to 11 am 70.7% 164
Departing 11 am to noon Insufficient sample 1
Departing noon to 1 pm 77.7% 358
Departing 1 pm to 2 pm Insufficient sample 7
Departing 2 pm to 3 pm 84.1% 283
Departing 3 pm to 4 pm 77.4% 274
Departing 4 pm to 5 pm 78.5% 312
Departing 5 pm to 6 pm 86.8% 53
Departing 6 pm to 7 pm 64.5% 355
Departing 7 pm to 8 pm 51.8% 112
Departing 8 pm to 9 pm 65.2% 233
Departing 9 pm to 10 pm 80.7% 332
Departing 10 pm to 11 pm Insufficient sample 26
Departing 11 pm to midnight Insufficient sample 2
Woman at an airport window watching a plane take off
Photo: Depositphotos (licensed stock, illustrative only). Credits

Sources & data dates

Source
U.S. DOT Bureau of Transportation Statistics, Reporting Carrier On-Time Performance (1987-present)
Period
September 2025 to August 2026 (12 months); month-of-year patterns September 2023 to August 2026
Data through
August 2026
Processed
2026-11-03
Scope
Nonstop scheduled flights from Houston, TX (IAH) to San Francisco, CA (SFO), one direction. Airlines that report to the DOT only.
Method
Rates use all scheduled flights as the denominator; cancelled and diverted flights count as not on time. Figures based on fewer than 50 scheduled flights are suppressed. Full methodology.

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