Route profile
MDW→SAT
Flight reliability, delays and best times to fly from Chicago to San Antonio, 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 54% of comparable major US routes (4,598 compared)
Calculated from 2,150 flights. How this is calculated · What counts as on time
MDW → SAT arrives on time 76.2% of the time; the return trip, SAT → MDW, arrives on time 84.1% of the time, a 7.9-point gap between the two directions of the same city pair.
MDW → SAT spends 18.8 minutes on the ground on a 1,036-mile trip: 14.8 minutes from pushback to wheels-up at MDW and 4.0 minutes from touchdown to gate at SAT.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
Reliability here swings unusually widely by season, a wider month-to-month spread than 94% of 3,357 comparable routes.
87.7% on time in a typical February, against 62.0% in July.
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 3,357 in the comparison.
What sets this route apart
Where MDW to SAT differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
MDW to SAT is at its best against routes of similar length for flights scheduled at 8 PM: 72.7% arrive on time, 7.2 points ahead of the 65.5% those routes manage at that hour.
Tuesday is the day MDW to SAT slips furthest against routes of similar length, 72.8% on time where they average 80.4%, 7.6 points lower. Against all other routes the gap is 8.8 points.
March is kinder to MDW to SAT than to routes of similar length: 85.0% on time against 75.1%, 9.9 points better. Against all other routes the gap is 7.1 points.
In June, MDW to SAT runs 9.1 points below routes of similar length, 62.4% on time to 71.5%. Against all other routes the gap is 10.3 points.
MDW to SAT against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 8 PM departures | 72.7% | routes of similar length | 65.5% | +7.2 pts | 187 here, 140,255 there |
| Weekday: Tuesday | 72.8% | routes of similar length | 80.4% | −7.6 pts | 302 here, 384,313 there |
| Month: March | 85.0% | routes of similar length | 75.1% | +9.9 pts | 173 here, 250,376 there |
| Month: June | 62.4% | routes of similar length | 71.5% | −9.1 pts | 189 here, 226,870 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
43 min late
against a median of 4 min early
Percentiles over 2,150 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SAT after arriving from MDW.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 42% | Likely to miss |
| 45 min | 23% | High risk |
| 60 min | 14% | Some risk |
| 90 min | 6.8% | Some risk |
| 120 min | 4.1% | 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 0.84% of the time and diverts 0.19% of the time, which a late arrival never shows up in.
Chance of missing is the share of 2,128 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 43 minutes late (90th-percentile gate arrival delay), over 2,150 operations.
Any other layover length: connection checker.
Best time to fly
MDW → SAT flights departing 5–9 AM arrived on time 85.5% of the time, against 60.8% for 9 PM–5 AM departures, a gap of 24.7 percentage points.
By departure window
By departure hour
- 12 AM to 6 AM: too few flights to score
- 7 AM: 91.0% on time from 146 flights
- 8 AM: 82.8% on time from 285 flights
- 9 AM: 87.0% on time from 382 flights
- 10 AM: 81.4% on time from 228 flights
- 11 AM to 6 PM: too few flights to score
- 7 PM: 69.6% on time from 139 flights
- 8 PM: 72.7% on time from 189 flights
- 9 PM: 62.1% on time from 365 flights
- 10 PM: 56.7% on time from 124 flights
- 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why MDW → SAT 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 MDW → SAT. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on MDW → SAT, at 49.2%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 85.5% of the time and 9 PM–5 AM departures 60.8%.
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 | 2,150 | 76.2% | 0.84% | -4 min | 7.0% |
Weekly and seasonal patterns
By day of week
Wednesday is historically the most reliable day and Tuesday the least, a gap of 10.6 percentage points.
By month
- Jan: 77.4%
- Feb: 87.7%
- Mar: 85.0%
- Apr: 74.7%
- May: 69.4%
- Jun: 62.4%
- Jul: 62.0%
- Aug: 78.2%
- Sep: 82.6%
- Oct: 82.8%
- Nov: 84.2%
- Dec: 80.0%
July is historically the weakest month and February the strongest, a spread of 25.7 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 77.3% against 79.6% in the 12 months before — declining by 2.3 percentage points.
Data and methodology
Calculated by FlyerIntel from 2,150 MDW → SAT 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