PlainFlights

Route · IAH → SFO · 2020–2025 BTS data

Houston to San Francisco

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), IAH to SFO (Houston to San Francisco) ranks #460 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

80.9%
On-time
+1.9 pts
vs US avg
70 min
Delay when late
17,301
Flights
#460 of 4927
Corpus placement

Cancelled

1.2%

Best Month

Sep 2025 89%

Worst Month

May 2024 57%

Distance

1,635 mi

Carriers

2

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 311 63 1 0 UA
Nov 2025 299 55 0 0 UA
Oct 2025 306 54 2 0 UA
Sep 2025 289 31 0 0 UA
Aug 2025 299 58 2 0 UA
Jul 2025 299 78 0 0 UA
Jun 2025 295 106 3 0 UA
May 2025 303 66 4 0 UA
Apr 2025 292 39 1 0 UA
Mar 2025 284 58 0 0 UA
Feb 2025 229 41 0 1 UA
Jan 2025 238 42 11 1 UA
Dec 2024 280 79 4 0 UA
Nov 2024 268 82 0 0 UA
Oct 2024 279 45 0 0 UA
Sep 2024 270 35 0 0 UA
Aug 2024 280 34 0 0 UA
Jul 2024 279 91 16 0 UA
Jun 2024 270 73 2 0 UA
May 2024 258 111 2 0 UA
Apr 2024 240 97 0 1 UA
Mar 2024 248 87 0 0 UA
Feb 2024 230 70 1 0 UA
Jan 2024 251 65 30 0 UA

IAH–SFO seasonal on-time pattern

Best: September (87.3%) · weakest: June (73.5%)

70%75%80%85%90% JanFebMarAprMayJunJulAugSepOctNovDec 78.9%

Strongest calendar month

September

87.3% on-time · ~238 flights/mo

Busiest calendar month

December

~265 flights/mo avg

Weakest calendar month

June

73.5% on-time · ~234 flights/mo

Cancellation Rate

1.2%

79 of 6,597 flights

Diversion Rate

0.0%

3 of 6,597 flights

Explore origin & destination

On-time and delay data for the airports this route connects.

IAH - Houston

Full on-time, delay-cause, and seasonal performance for Houston, TX.

IAH on-time profile

SFO - San Francisco

Full on-time, delay-cause, and seasonal performance for San Francisco, CA.

SFO on-time profile

Compare the two airports

See IAH and SFO side by side on delays, cancellations, and reliability.

Compare IAH vs SFO

Origin-hub reliability standing

Mid-pack among IAH departures

From IAH, this corridor sits with 79 other 75–85% on-time routes out of 102 tracked departures, not the hub's reliability leaders (17 at ≥85%) and not the softest ( 6 below 75%). Destination: San Francisco · fleet on-time rank #2783 of 4927.

What the Data Says About IAH to SFO

17,301 tracked flights put the IAH to SFO pairing (Houston to San Francisco) at a 80.9% on-time rate, squarely in line with the wider network. Delays that do occur run 69.8 minutes on average. Across the 1,635-mile route and its 2 carriers, the trailing 24 months show 1.2% cancelled and 0.0% diverted (6,597 flights sampled).

The monthly split is wide on this route: Sep 2025 posted the strongest performance at 89% on-time, while May 2024 came in at just 57% - a 32-point swing worth factoring into travel timing.

On the multi-year calendar, IAH–SFO peaks in September at 87.3% on-time while December carries the heaviest traffic (~265 flights per month) ; the softest month is June at 73.5%, a 13.8-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does IAH to SFO rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, IAH to SFO ranks #460 of 4927 tracked domestic routes by total flights (most flights = #1). That ordinal matches our busiest-routes listing (total_flights DESC). See /methodology#corpus-placement for the exact sort basis.
How often are flights delayed from IAH to SFO? ▼
Flights from Houston to San Francisco have a 80.9% on-time rate based on 17,301 flights. The average delay is 69.8 minutes. The best recent month was Sep 2025 with 89% on-time.
What is the cancellation rate for IAH to SFO? ▼
Over the last 24 months, 1.2% of flights on this route were cancelled (79 of 6,597 flights) and 0.0% were diverted.
How far is the flight from IAH to SFO? ▼
The flight distance from Houston (IAH) to San Francisco (SFO) is approximately 1,635 miles. This route is served by 2 carriers.
When is the best time to fly from IAH to SFO? ▼
The best recent month for on-time performance was Sep 2025 (89% on-time). The worst was May 2024 (57% on-time). Consider booking during months with historically better performance.

Airports on this route

IAH Airport

Houston
SFO Airport

San Francisco
Data source

Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.

Read our methodology - how this data is sourced, computed, and verified.

Using IAH–SFO data

IAH–SFO is mid-pack at 80.9% on-time; month and carrier mix move more than the corridor headline.

  • Compare IAH and SFO airport profiles: delay causes and top routes differ even on the same corridor. IAH airport
  • If your dates flex, September (87.3% on-time) beats June (73.5%) on this corridor. Seasonal chart
  • 4 other routes post a similar 80.9% on-time rate; compare before you commit to this pairing. Similar routes

On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.

Data sourced from U.S. Department of Transportation Bureau of Transportation Statistics (BTS) On-Time Performance data. See our methodology for details. Retrieved and formatted by PlainFlights

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.