Route on-time record
MDW to SAT: most on-time flights and the best time to fly
Chicago (Chicago Midway International Airport) to San Antonio (San Antonio International Airport). 685 nonstop flights in Jun 2025 to May 2026, 78% arrived within 15 minutes and 1.0% were cancelled. The most reliable flight number was Southwest 2168 at 10:10 AM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
MDW → SAT
Chicago to San Antonio: 685 nonstop flights a year
On time (12 months)
78%
Cancelled
1.0%
avg delay 14 min
Best time to leave
Before 9 AM
85% on time vs 66% after 9 PM
Most reliable airline
Southwest
77% chance on time
Lowest nonstop fare seen in the next two months: $283 (Southwest 3426 on 2026-10-21). 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 2168
10:10 AM → 1:00 PM2h 50m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 2471; its record covers all of them.
80%
chance on time
- On time (history)
- 81%
- Cancelled
- 1.1%
- Avg arrival delay
- 8 min
- Arrived on time 81% of the time (86 flights, Jun 2025 to May 2026).
- Departs inside MDW's trouble window: 50% of its 30 ground stops and delay programs started between 7 AM and 1 PM.
Moderate track record · 86 flights
Find Southwest 2168 fares Opens this date on Aviasales#2 · Southwest 2350
9:40 PM → 12:30 AM2h 50m nonstop
Local times, typical schedule. Last flown 2026-05-31.
73%
chance on time
- On time (history)
- 74%
- Cancelled
- 1.8%
- Avg arrival delay
- 23 min
- Arrived on time 74% of the time (54 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (After 9 PM: 66% on time; Before 9 AM: 85%).
- Departs outside MDW's trouble window (7 AM to 1 PM, when 50% of its 30 ground stops and delay programs started).
- Short track record (54 flights), so its score leans on the airline's record at this hour.
Limited track record · 54 flights
Find Southwest 2350 fares Opens this date on Aviasales#3 · Southwest 3998
9:55 PM → 12:50 AM2h 55m nonstop
Local times, typical schedule. Last flown 2026-04-06.
68%
chance on time
- On time (history)
- 68%
- Cancelled
- 6.1%
- Avg arrival delay
- 29 min
- Arrived on time 68% of the time (31 flights, Jun 2025 to May 2026).
- Cancelled 6.1% of the time (2 of 33).
- Leaves in this route's least on-time window (After 9 PM: 66% on time; Before 9 AM: 85%).
- Departs outside MDW's trouble window (7 AM to 1 PM, when 50% of its 30 ground stops and delay programs started).
Limited track record · 31 flights
Find Southwest 3998 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Southwest Airlines77%
685 flights · 78% on time as flown · 1.0% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM85%
239 flights · avg delay 7 min
- 9 AM to noon81%
109 flights · avg delay 8 min
- 3 to 6 PM70%
76 flights · avg delay 24 min
- 6 to 9 PM80%
90 flights · avg delay 12 min
- After 9 PM66%
163 flights · avg delay 24 min
Best day: Wednesday (83%). Worst: Friday (73%).
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)34%
- Air traffic control and airport volume16%
- 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
MDW to SAT questions
- What time of day is best to fly MDW to SAT?
- Before 9 AM: 85% of flights arrived on time, against 66% for departures after 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 MDW to SAT?
- Southwest, with a season-adjusted 77% 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 MDW to SAT?
- July (59% on time); the best was February (88%), 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 MDW
- SAT to MDW (return)
- MDW to ATL 80%
- MDW to PHX 76%
- MDW to MCO 77%
- MDW to MSP 78%
- MDW to LAS 77%
- MDW to DEN 73%
- MDW to LGA 69%
- MDW to DAL 77%
- MDW to DCA 69%
- MDW to MCI 79%
- MDW to BNA 80%
- MDW to BWI 79%
Live status: FAA delays and ground stops