Route on-time record
SEA to SAT: most on-time flights and the best time to fly
Seattle (Seattle–Tacoma International Airport) to San Antonio (San Antonio International Airport). 558 nonstop flights in Jun 2025 to May 2026, 75% arrived within 15 minutes and 1.1% were cancelled. The most reliable flight number was Alaska 520 at 11:35 PM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
SEA → SAT
Seattle to San Antonio: 558 nonstop flights a year
On time (12 months)
75%
Cancelled
1.1%
avg delay 12 min
Best time to leave
3 to 6 PM
82% on time vs 66% noon to 3 PM
Most reliable airline
Alaska
75% chance on time
Lowest nonstop fare seen in the next two months: $378 (United 2281 on 2026-10-23). 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 · Alaska 520
11:35 PM → 5:40 AM4h 05m nonstop
Local times, typical schedule. Last flown 2026-05-31.
77%
chance on time
- On time (history)
- 78%
- Cancelled
- 0.0%
- Avg arrival delay
- 12 min
- Arrived on time 78% of the time (46 flights, Jun 2025 to May 2026).
- Never cancelled in 46 scheduled flights.
- Departs outside SEA's trouble window (4 PM to 10 PM, when 54% of its 68 ground stops and delay programs started).
Limited track record · 46 flights
Find Alaska 520 fares Opens this date on Aviasales#2 · Alaska 494
10:53 AM → 4:54 PM4h 01m nonstop
Local times, typical schedule. Last flown 2026-05-31.
72%
chance on time
- On time (history)
- 72%
- Cancelled
- 0.9%
- Avg arrival delay
- 13 min
- Arrived on time 72% of the time (331 flights, Jun 2025 to May 2026).
- Departs outside SEA's trouble window (4 PM to 10 PM, when 54% of its 68 ground stops and delay programs started).
Strong track record · 331 flights
Find Alaska 494 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Alaska Airlines75%
558 flights · 75% on time as flown · 1.1% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- 9 AM to noon79%
213 flights · avg delay 10 min
- Noon to 3 PM66%
152 flights · avg delay 17 min
- 3 to 6 PM82%
52 flights · avg delay 8 min
- After 9 PM78%
127 flights · avg delay 10 min
Best day: Tuesday (83%). Worst: Sunday (71%).
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 aircraft47%
- Airline (crew, maintenance, boarding)39%
- Air traffic control and airport volume12%
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
SEA to SAT questions
- What time of day is best to fly SEA to SAT?
- 3 to 6 PM: 82% of flights arrived on time, against 66% for departures noon to 3 PM.
- Which airline is most on time from SEA to SAT?
- Alaska, with a season-adjusted 75% chance of operating and arriving on time over 558 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 SEA to SAT?
- June (64% on time); the best was February (86%), 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 SEA
- SAT to SEA (return)
- SEA to LAX 83%
- SEA to PHX 79%
- SEA to SFO 69%
- SEA to ANC 74%
- SEA to DEN 77%
- SEA to LAS 77%
- SEA to ORD 75%
- SEA to GEG 81%
- SEA to DFW 77%
- SEA to PDX 82%
- SEA to SAN 78%
- SEA to SMF 81%
Most on-time flights from SEA on every route →
Live status: FAA delays and ground stops