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Route on-time record

SFO to IAH: most on-time flights and the best time to fly

San Francisco (San Francisco International Airport) to Houston (George Bush Intercontinental Airport). 3,596 nonstop flights in Jun 2025 to May 2026, 85% arrived within 15 minutes and 0.4% were cancelled. The most reliable flight number was United 686 at 7:00 AM.

Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.

SFO → IAH

San Francisco to Houston: 3,596 nonstop flights a year

On time (12 months)

85%

Cancelled

0.4%

avg delay 9 min

Best time to leave

Before 9 AM

95% on time vs 76% 9 AM to noon

Most reliable airline

United

84% chance on time

Check SFO to IAH fares

Lowest nonstop fare seen in the next two months: $278 (United 505 on 2026-11-03). Fares open on our travel partner (Aviasales). Pick the flight number you chose here.

Most reliable nonstop flights

Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.

  1. #1 · United 686

    7:00 AM → 1:00 PM4h 00m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    95%

    chance on time

    On time (history)
    97%
    Cancelled
    1.1%
    Avg arrival delay
    4 min
    • Arrived on time 97% of the time (87 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 95% on time; 9 AM to noon: 76%).
    • Departs inside SFO's trouble window: 61% of its 333 ground stops and delay programs started between 7 AM and 1 PM.
    • Lands inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.

    Moderate track record · 87 flights

    Find United 686 fares Opens this date on Aviasales

  2. #2 · United 2168

    5:00 AM → 10:51 AM3h 51m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    95%

    chance on time

    On time (history)
    97%
    Cancelled
    2.3%
    Avg arrival delay
    2 min
    • Arrived on time 97% of the time (86 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 95% on time; 9 AM to noon: 76%).
    • Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).

    Moderate track record · 86 flights

    Find United 2168 fares Opens this date on Aviasales

  3. #3 · United 1702

    6:54 PM → 12:59 AM4h 05m nonstop

    Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as United 2047; its record covers all of them.

    88%

    chance on time

    On time (history)
    90%
    Cancelled
    0.0%
    Avg arrival delay
    6 min
    • Arrived on time 90% of the time (106 flights, Jun 2025 to May 2026).
    • Never cancelled in 106 scheduled flights.
    • Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).

    Moderate track record · 106 flights

    Find United 1702 fares Opens this date on Aviasales

  4. #4 · United 2110

    8:55 AM → 3:07 PM4h 12m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    87%

    chance on time

    On time (history)
    100%
    Cancelled
    0.0%
    Avg arrival delay
    1 min
    • Arrived on time 100% of the time (11 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 95% on time; 9 AM to noon: 76%).
    • Departs inside SFO's trouble window: 61% of its 333 ground stops and delay programs started between 7 AM and 1 PM.
    • Lands inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.

    Limited track record · 11 flights

    Find United 2110 fares Opens this date on Aviasales

  5. #5 · United 787

    2:22 PM → 8:29 PM4h 07m nonstop

    Local times, typical schedule. Last flown 2026-04-29.

    86%

    chance on time

    On time (history)
    94%
    Cancelled
    0.0%
    Avg arrival delay
    4 min
    • Arrived on time 94% of the time (32 flights, Jun 2025 to May 2026).
    • Never cancelled in 32 scheduled flights.
    • Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).
    • Short track record (32 flights), so its score leans on the airline's record at this hour.

    Limited track record · 32 flights

    Find United 787 fares Opens this date on Aviasales

  6. #6 · United 1439

    9:20 AM → 3:13 PM3h 53m nonstop

    Local times, typical schedule. Last flown 2026-03-28.

    86%

    chance on time

    On time (history)
    89%
    Cancelled
    0.0%
    Avg arrival delay
    16 min
    • Arrived on time 89% of the time (61 flights, Jun 2025 to May 2026).
    • Never cancelled in 61 scheduled flights.
    • Leaves in this route's least on-time window (9 AM to noon: 76% on time; Before 9 AM: 95%).
    • Departs inside SFO's trouble window: 61% of its 333 ground stops and delay programs started between 7 AM and 1 PM.

    Moderate track record · 61 flights

    Find United 1439 fares Opens this date on Aviasales

  7. #7 · United 604

    12:45 AM → 6:28 AM3h 43m nonstop

    Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as United 2402; its record covers all of them.

    85%

    chance on time

    On time (history)
    84%
    Cancelled
    0.0%
    Avg arrival delay
    8 min
    • Arrived on time 84% of the time (88 flights, Jun 2025 to May 2026).
    • Never cancelled in 88 scheduled flights.
    • Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).

    Moderate track record · 88 flights

    Find United 604 fares Opens this date on Aviasales

  8. #8 · United 2498

    9:10 AM → 3:05 PM3h 55m nonstop

    Local times, typical schedule. Last flown 2026-05-20.

    84%

    chance on time

    On time (history)
    85%
    Cancelled
    0.0%
    Avg arrival delay
    12 min
    • Arrived on time 85% of the time (53 flights, Jun 2025 to May 2026).
    • Never cancelled in 53 scheduled flights.
    • Leaves in this route's least on-time window (9 AM to noon: 76% on time; Before 9 AM: 95%).
    • Departs inside SFO's trouble window: 61% of its 333 ground stops and delay programs started between 7 AM and 1 PM.

    Limited track record · 53 flights

    Find United 2498 fares Opens this date on Aviasales

  9. #9 · United 505

    11:59 PM → 5:52 AM3h 52m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    84%

    chance on time

    On time (history)
    84%
    Cancelled
    0.3%
    Avg arrival delay
    11 min
    • Arrived on time 84% of the time (300 flights, Jun 2025 to May 2026).
    • Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).

    Strong track record · 300 flights

    Find United 505 fares Opens this date on Aviasales

  10. #10 · United 2305

    4:45 PM → 10:52 PM4h 06m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    83%

    chance on time

    On time (history)
    83%
    Cancelled
    0.3%
    Avg arrival delay
    12 min
    • Arrived on time 83% of the time (295 flights, Jun 2025 to May 2026).
    • Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).

    Strong track record · 295 flights

    Find United 2305 fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

  • United Airlines84%

    3,596 flights · 85% on time as flown · 0.4% cancel

On time by departure time

All airlines, scheduled local departure, Jun 2025 to May 2026.

  • Before 9 AM95%

    758 flights · avg delay 4 min

  • 9 AM to noon76%

    698 flights · avg delay 13 min

  • Noon to 3 PM79%

    726 flights · avg delay 11 min

  • 3 to 6 PM83%

    369 flights · avg delay 12 min

  • 6 to 9 PM87%

    316 flights · avg delay 8 min

  • After 9 PM86%

    729 flights · avg delay 9 min

Best day: Wednesday (87%). Worst: Friday (82%).

Smarter routing

Nearby airports that run more on time

  • SJC → HOU 91% chance on time

    Norman Y. Mineta San Jose International Airport to William P. Hobby Airport · 365 flights a year · 54 mi from your airports · yours: 84%

    Rank flightsFares

On time by month

All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.

J
83
F
89
M
86
A
89
M
83
J
79
J
78
A
82
S
91
O
90
N
84
D
80

What delays this route

  • Airline (crew, maintenance, boarding)37%
  • Late-arriving aircraft31%
  • Air traffic control and airport volume31%

Share of delay minutes by the cause airlines report to the US DOT.

Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure

SFO to IAH questions

What time of day is best to fly SFO to IAH?
Before 9 AM: 95% of flights arrived on time, against 76% for departures 9 AM to noon. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
Which airline is most on time from SFO to IAH?
United, with a season-adjusted 84% chance of operating and arriving on time over 3,596 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
What is the worst month for delays on SFO to IAH?
July (78% on time); the best was September (91%), averaged over Jun 2023 to May 2026.
Is this a prediction for my flight?
No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.

More routes from SFO

Live status: FAA delays and ground stops