Route profile
SAT→MDW
Flight reliability, delays and best times to fly from San Antonio to Chicago, 1,036 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 90% of comparable major US routes (4,598 compared)
Calculated from 2,168 flights. How this is calculated · What counts as on time
SAT → MDW arrives on time 84.1% of the time; the return trip, MDW → SAT, arrives on time 76.2% of the time, a 7.9-point gap between the two directions of the same city pair.
SAT → MDW spends 16.0 minutes on the ground on a 1,036-mile trip: 11.0 minutes from pushback to wheels-up at SAT and 5.0 minutes from touchdown to gate at MDW.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
Reliability on this route has fallen unusually sharply over the past year, a bigger swing than 97% of 5,368 comparable routes.
76.8% on time over the most recent 12 months (2025-08 to 2026-07), against 90.2% in the 12 months before (2024-08 to 2025-07), a change of 13.4 points.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 5,368 in the comparison.
What sets this route apart
Where SAT to MDW differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
SAT to MDW is at its best against routes of similar length for flights scheduled at 4 PM: 82.5% arrive on time, 15.1 points ahead of the 67.4% those routes manage at that hour. Against all other routes the gap is 11.8 points.
SAT to MDW holds up on Saturdays better than routes of similar length do: 88.8% on time to their 77.0%, a 11.8 points lead. Against all other routes the gap is 9.7 points.
July is kinder to SAT to MDW than to routes of similar length: 81.9% on time against 67.9%, 14 points better. Against all other routes the gap is 12.2 points.
Southwest Airlines does better on SAT to MDW than on its routes of similar length: 84.1% on time here, 75.3% there, 8.8 points apart. Against all other routes the gap is 6.7 points.
SAT to MDW against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 4 PM departures | 82.5% | routes of similar length | 67.4% | +15.1 pts | 171 here, 148,764 there |
| Weekday: Saturday | 88.8% | routes of similar length | 77.0% | +11.8 pts | 267 here, 378,844 there |
| Month: July | 81.9% | routes of similar length | 67.9% | +14.0 pts | 254 here, 308,175 there |
| Airline: Southwest Airlines | 84.1% | routes of similar length | 75.3% | +8.8 pts | 2,143 here, 656,372 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 1,036 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
When it goes wrong
July 2023 – July 2026
25 min late
against a median of 4 min early
Percentiles over 2,168 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at MDW after arriving from SAT.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 37% | Likely to miss |
| 45 min | 15% | High risk |
| 60 min | 7.7% | Some risk |
| 90 min | 3.5% | Low risk |
| 120 min | 1.5% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 0.83% of the time and diverts 0.32% of the time, which a late arrival never shows up in.
Chance of missing is the share of 2,143 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 25 minutes late (90th-percentile gate arrival delay), over 2,168 operations.
Any other layover length: connection checker.
Best time to fly
SAT → MDW flights departing 5–9 AM arrived on time 92.6% of the time, against 74.7% for 3–6 PM departures, a gap of 17.9 percentage points.
By departure window
By departure hour
- 12 AM to 4 AM: too few flights to score
- 5 AM: 94.8% on time from 350 flights
- 6 AM: 91.3% on time from 370 flights
- 7 AM: 90.2% on time from 157 flights
- 8 AM to 1 PM: too few flights to score
- 2 PM: 76.3% on time from 337 flights
- 3 PM: 70.7% on time from 409 flights
- 4 PM: 82.5% on time from 175 flights
- 5 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why SAT → MDW runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for SAT → MDW. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on SAT → MDW, at 50.4%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 92.6% of the time and 3–6 PM departures 74.7%.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| Southwest Airlines | 2,168 | 84.1% | 0.83% | -4 min | 3.5% |
Weekly and seasonal patterns
By day of week
Saturday is historically the most reliable day and Thursday the least, a gap of 9.0 percentage points.
By month
- Jan: 85.0%
- Feb: 89.9%
- Mar: 76.6%
- Apr: 83.1%
- May: 78.8%
- Jun: 81.4%
- Jul: 81.9%
- Aug: 87.2%
- Sep: 87.8%
- Oct: 89.8%
- Nov: 88.2%
- Dec: 82.2%
March is historically the weakest month and February the strongest, a spread of 13.3 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 76.8% against 90.2% in the 12 months before — declining by 13.4 percentage points.
Data and methodology
Calculated by FlyerIntel from 2,168 SAT → MDW flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed