Route on-time record
SAT to MDW: most on-time flights and the best time to fly
San Antonio (San Antonio International Airport) to Chicago (Chicago Midway International Airport). 685 nonstop flights in Jun 2025 to May 2026, 81% arrived within 15 minutes and 0.9% were cancelled. The most reliable flight number was Southwest 4168 at 9:00 AM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
SAT → MDW
San Antonio to Chicago: 685 nonstop flights a year
On time (12 months)
81%
Cancelled
0.9%
avg delay 10 min
Best time to leave
Before 9 AM
94% on time vs 63% 3 to 6 PM
Most reliable airline
Southwest
80% chance on time
Lowest nonstop fare seen in the next two months: $305 (Southwest 4109 on 2026-10-27). 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 · Southwest 4168
9:00 AM → 11:40 AM2h 35m nonstop
Local times, typical schedule. Last flown 2026-05-31.
91%
chance on time
- On time (history)
- 98%
- Cancelled
- 1.8%
- Avg arrival delay
- 1 min
- Arrived on time 98% of the time (54 flights, Jun 2025 to May 2026).
- Lands inside MDW's trouble window: 50% of its 30 ground stops and delay programs started between 7 AM and 1 PM.
- Short track record (54 flights), so its score leans on the airline's record at this hour.
Limited track record · 54 flights
Find Southwest 4168 fares Opens this date on Aviasales#2 · Southwest 1590
9:25 AM → 11:55 AM2h 30m nonstop
Local times, typical schedule. Last flown 2026-04-06.
81%
chance on time
- On time (history)
- 74%
- Cancelled
- 6.1%
- Avg arrival delay
- 12 min
- Arrived on time 74% of the time (31 flights, Jun 2025 to May 2026).
- Cancelled 6.1% of the time (2 of 33).
- Lands inside MDW's trouble window: 50% of its 30 ground stops and delay programs started between 7 AM and 1 PM.
- Short track record (31 flights), so its score leans on the airline's record at this hour.
Limited track record · 31 flights
Find Southwest 1590 fares Opens this date on Aviasales#3 · Southwest 2743
2:35 PM → 5:10 PM2h 35m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 2170; its record covers all of them.
69%
chance on time
- On time (history)
- 67%
- Cancelled
- 0.0%
- Avg arrival delay
- 17 min
- Arrived on time 67% of the time (54 flights, Jun 2025 to May 2026).
- Never cancelled in 54 scheduled flights.
- 58% of its delay minutes came from the plane arriving late from an earlier flight.
- Short track record (54 flights), so its score leans on the airline's record at this hour.
Limited track record · 54 flights
Find Southwest 2743 fares Opens this date on Aviasales#4 · Southwest 457
3:25 PM → 5:55 PM2h 30m nonstop
Local times, typical schedule. Last flown 2026-04-06.
62%
chance on time
- On time (history)
- 42%
- Cancelled
- 0.0%
- Avg arrival delay
- 30 min
- Arrived on time 42% of the time (33 flights, Jun 2025 to May 2026).
- Never cancelled in 33 scheduled flights.
- Leaves in this route's least on-time window (3 to 6 PM: 63% on time; Before 9 AM: 94%).
- Short track record (33 flights), so its score leans on the airline's record at this hour.
Limited track record · 33 flights
Find Southwest 457 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Southwest Airlines80%
685 flights · 81% on time as flown · 0.9% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM94%
222 flights · avg delay 4 min
- 9 AM to noon87%
115 flights · avg delay 5 min
- Noon to 3 PM72%
184 flights · avg delay 15 min
- 3 to 6 PM63%
122 flights · avg delay 19 min
- 6 to 9 PM83%
42 flights · avg delay 10 min
Best day: Saturday (90%). Worst: Thursday (79%).
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 aircraft48%
- Airline (crew, maintenance, boarding)27%
- Air traffic control and airport volume24%
- Severe weather1%
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
SAT to MDW questions
- What time of day is best to fly SAT to MDW?
- Before 9 AM: 94% of flights arrived on time, against 63% for departures 3 to 6 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 SAT to MDW?
- Southwest, with a season-adjusted 80% chance of operating and arriving on time over 685 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 SAT to MDW?
- March (77% on time); the best was February (90%), 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 SAT
- MDW to SAT (return)
- SAT to DFW 77%
- SAT to ATL 85%
- SAT to DEN 81%
- SAT to DAL 84%
- SAT to PHX 83%
- SAT to IAH 81%
- SAT to LAS 83%
- SAT to ORD 76%
- SAT to LAX 87%
- SAT to HOU 74%
- SAT to CLT 86%
- SAT to MCO 77%
Live status: FAA delays and ground stops