Route on-time record
IAH to SAT: most on-time flights and the best time to fly
Houston (George Bush Intercontinental Airport) to San Antonio (San Antonio International Airport). 2,452 nonstop flights in Jun 2025 to May 2026, 83% arrived within 15 minutes and 0.9% were cancelled. The most reliable flight number was United 2250 at 7:35 AM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
IAH → SAT
Houston to San Antonio: 2,452 nonstop flights a year
On time (12 months)
83%
Cancelled
0.9%
avg delay 12 min
Best time to leave
Before 9 AM
95% on time vs 74% 6 to 9 PM
Most reliable airline
United
82% chance on time
Lowest nonstop fare seen in the next two months: $219 (United 2250 on 2026-10-22). 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 · United 2250
7:35 AM → 8:42 AM1h 07m nonstop
Local times, typical schedule. Last flown 2026-05-31.
91%
chance on time
- On time (history)
- 93%
- Cancelled
- 0.8%
- Avg arrival delay
- 4 min
- Arrived on time 93% of the time (126 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 95% on time; 6 to 9 PM: 74%).
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
Moderate track record · 126 flights
Find United 2250 fares Opens this date on Aviasales#2 · United 468
11:55 AM → 1:08 PM1h 13m nonstop
Local times, typical schedule. Last flown 2026-05-20.
87%
chance on time
- On time (history)
- 88%
- Cancelled
- 0.0%
- Avg arrival delay
- 9 min
- Arrived on time 88% of the time (282 flights, Jun 2025 to May 2026).
- Never cancelled in 283 scheduled flights.
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
Strong track record · 282 flights
Find United 468 fares Opens this date on Aviasales#3 · United 697
2:32 PM → 3:46 PM1h 14m nonstop
Local times, typical schedule. Last flown 2026-05-31.
86%
chance on time
- On time (history)
- 88%
- Cancelled
- 0.0%
- Avg arrival delay
- 6 min
- Arrived on time 88% of the time (159 flights, Jun 2025 to May 2026).
- Never cancelled in 159 scheduled flights.
- Departs inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.
Moderate track record · 159 flights
Find United 697 fares Opens this date on Aviasales#4 · United 1371
9:43 AM → 10:47 AM1h 07m nonstop
Local times, typical schedule. Last flown 2026-05-20.
84%
chance on time
- On time (history)
- 85%
- Cancelled
- 0.0%
- Avg arrival delay
- 7 min
- Arrived on time 85% of the time (220 flights, Jun 2025 to May 2026).
- Never cancelled in 220 scheduled flights.
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
Strong track record · 220 flights
Find United 1371 fares Opens this date on Aviasales#5 · SkyWest 5379 · sold as United Express, Delta Connection, American Eagle or Alaska
4:35 PM → 5:44 PM1h 09m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as SkyWest 5807; its record covers all of them.
81%
chance on time
- On time (history)
- 87%
- Cancelled
- 3.1%
- Avg arrival delay
- 8 min
- Arrived on time 87% of the time (31 flights, Jun 2025 to May 2026).
- Cancelled 3.1% of the time (1 of 32).
- Departs inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.
- Short track record (31 flights), so its score leans on the airline's record at this hour.
Limited track record · 31 flights
Find 4:35 PM flight fares Opens this date on Aviasales#6 · United 1464
12:01 PM → 1:14 PM1h 13m nonstop
Local times, typical schedule. Last flown 2026-03-28.
81%
chance on time
- On time (history)
- 79%
- Cancelled
- 0.0%
- Avg arrival delay
- 8 min
- Arrived on time 79% of the time (24 flights, Jun 2025 to May 2026).
- Departs inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.
- Short track record (24 flights), so its score leans on the airline's record at this hour.
Limited track record · 24 flights
Find United 1464 fares Opens this date on Aviasales#7 · United 2198
9:50 PM → 10:57 PM1h 07m nonstop
Local times, typical schedule. Last flown 2026-05-31.
79%
chance on time
- On time (history)
- 77%
- Cancelled
- 2.5%
- Avg arrival delay
- 20 min
- Arrived on time 77% of the time (39 flights, Jun 2025 to May 2026).
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
- Short track record (39 flights), so its score leans on the airline's record at this hour.
Limited track record · 39 flights
Find United 2198 fares Opens this date on Aviasales#8 · United 1407
4:33 PM → 5:43 PM1h 10m nonstop
Local times, typical schedule. Last flown 2026-04-29.
77%
chance on time
- On time (history)
- 75%
- Cancelled
- 0.0%
- Avg arrival delay
- 15 min
- Arrived on time 75% of the time (32 flights, Jun 2025 to May 2026).
- Never cancelled in 32 scheduled flights.
- Departs inside IAH's trouble window: 60% of its 92 ground stops and delay programs started between noon and 6 PM.
- Short track record (32 flights), so its score leans on the airline's record at this hour.
Limited track record · 32 flights
Find United 1407 fares Opens this date on Aviasales#9 · United 1528
8:12 PM → 9:25 PM1h 13m nonstop
Local times, typical schedule. Last flown 2026-03-28.
77%
chance on time
- On time (history)
- 77%
- Cancelled
- 8.3%
- Avg arrival delay
- 39 min
- Arrived on time 77% of the time (22 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (6 to 9 PM: 74% on time; Before 9 AM: 95%).
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
- Short track record (22 flights), so its score leans on the airline's record at this hour.
Limited track record · 22 flights
Find United 1528 fares Opens this date on Aviasales#10 · United 1542
7:50 PM → 9:03 PM1h 13m nonstop
Local times, typical schedule. Last flown 2026-05-31.
77%
chance on time
- On time (history)
- 77%
- Cancelled
- 1.2%
- Avg arrival delay
- 13 min
- Arrived on time 77% of the time (336 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (6 to 9 PM: 74% on time; Before 9 AM: 95%).
- Departs outside IAH's trouble window (noon to 6 PM, when 60% of its 92 ground stops and delay programs started).
Strong track record · 336 flights
Find United 1542 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- United Airlines82%
2,363 flights · 83% on time as flown · 0.8% cancel
- SkyWest Airlines (sold as United Express, Delta Connection, American Eagle or Alaska)80%
89 flights · 77% on time as flown · 1.0% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM95%
337 flights · avg delay 3 min
- 9 AM to noon87%
384 flights · avg delay 7 min
- Noon to 3 PM84%
538 flights · avg delay 11 min
- 3 to 6 PM79%
207 flights · avg delay 14 min
- 6 to 9 PM74%
728 flights · avg delay 18 min
- After 9 PM82%
258 flights · avg delay 15 min
Best day: Tuesday (83%). Worst: Friday (77%).
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.
What delays this route
- Late-arriving aircraft43%
- Airline (crew, maintenance, boarding)37%
- Air traffic control and airport volume12%
- Severe weather8%
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
IAH to SAT questions
- What time of day is best to fly IAH to SAT?
- Before 9 AM: 95% of flights arrived on time, against 74% for departures 6 to 9 PM. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
- Which airline is most on time from IAH to SAT?
- United, with a season-adjusted 82% chance of operating and arriving on time over 2,363 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 IAH to SAT?
- July (66% on time); the best was November (85%), 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 IAH
- SAT to IAH (return)
- IAH to ORD 75%
- IAH to DFW 75%
- IAH to LAX 83%
- IAH to ATL 77%
- IAH to DEN 81%
- IAH to LGA 72%
- IAH to MIA 78%
- IAH to EWR 74%
- IAH to MCO 81%
- IAH to SFO 79%
- IAH to LAS 82%
- IAH to DCA 75%
Live status: FAA delays and ground stops