Route profile
SAN→MDW
Flight reliability, delays and best times to fly from San Diego to Chicago, 1,728 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 65% of comparable major US routes (4,598 compared)
Calculated from 3,274 flights. How this is calculated · What counts as on time
SAN → MDW arrives on time 77.6% of the time; the return trip, MDW → SAN, arrives on time 74.7% of the time, a 2.9-point gap between the two directions of the same city pair.
SAN → MDW spends 22.6 minutes on the ground on a 1,728-mile trip: 17.8 minutes from pushback to wheels-up at SAN and 4.7 minutes from touchdown to gate at MDW.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
This route has stayed remarkably steady year over year, a smaller swing than 93% of 5,368 comparable routes.
77.6% on time over the most recent 12 months (2025-08 to 2026-07), against 78.0% in the 12 months before (2024-08 to 2025-07), virtually unchanged.
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 SAN to MDW differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
SAN to MDW struggles most at 3 PM: 50.0% of its flights scheduled then arrive on time, 22.5 points behind the 72.5% on routes of similar length at the same hour. Against all other routes the gap is 22.7 points.
SAN to MDW is at its best against routes of similar length for flights scheduled at 10 PM: 95.2% arrive on time, 19.4 points ahead of the 75.8% those routes manage at that hour. Against all other routes the gap is 23.6 points.
SAN to MDW holds up on Saturdays better than routes of similar length do: 85.8% on time to their 78.8%, a 7 points lead. Against all other routes the gap is 6.7 points.
In October, SAN to MDW runs 5.4 points below routes of similar length, 77.9% on time to 83.3%. Against all other routes the gap is 5.1 points.
Southwest Airlines does better on SAN to MDW than on its routes of similar length: 77.6% on time here, 75.1% there, 2.5 points apart.
SAN to MDW against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 3 PM departures | 50.0% | routes of similar length | 72.5% | −22.5 pts | 148 here, 68,989 there |
| Hour: 10 PM departures | 95.2% | routes of similar length | 75.8% | +19.4 pts | 145 here, 31,849 there |
| Weekday: Saturday | 85.8% | routes of similar length | 78.8% | +7.0 pts | 388 here, 187,812 there |
| Month: October | 77.9% | routes of similar length | 83.3% | −5.4 pts | 263 here, 117,214 there |
| Airline: Southwest Airlines | 77.6% | routes of similar length | 75.1% | +2.5 pts | 3,226 here, 264,090 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 1,728 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
38 min late
against a median of 3 min early
Percentiles over 3,274 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at MDW after arriving from SAN.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 42% | Likely to miss |
| 45 min | 22% | High risk |
| 60 min | 12% | Some risk |
| 90 min | 5.6% | Some risk |
| 120 min | 2.6% | 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 0.86% of the time and diverts 0.61% of the time, which a late arrival never shows up in.
Chance of missing is the share of 3,226 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 38 minutes late (90th-percentile gate arrival delay), over 3,274 operations.
Any other layover length: connection checker.
Best time to fly
SAN → MDW flights departing 9 PM–5 AM arrived on time 95.2% of the time, against 63.9% for 6–9 PM departures, a gap of 31.3 percentage points.
By departure window
By departure hour
- 12 AM to 5 AM: too few flights to score
- 6 AM: 92.1% on time from 527 flights
- 7 AM: 90.9% on time from 424 flights
- 8 AM to 9 AM: too few flights to score
- 10 AM: 79.9% on time from 159 flights
- 11 AM: 73.7% on time from 309 flights
- 12 PM: 75.7% on time from 247 flights
- 1 PM: 67.8% on time from 155 flights
- 2 PM: too few flights to score
- 3 PM: 50.0% on time from 151 flights
- 4 PM: 78.7% on time from 128 flights
- 5 PM: 70.1% on time from 255 flights
- 6 PM: 62.2% on time from 271 flights
- 7 PM: 65.1% on time from 212 flights
- 8 PM to 9 PM: too few flights to score
- 10 PM: 95.2% on time from 149 flights
- 11 PM: too few flights to score
Why SAN → 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 SAN → MDW. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on SAN → MDW, at 54.1%: flights here mostly leave late because the plane came in late, and the day shows it: 9 PM–5 AM departures arrived on time 95.2% of the time and 6–9 PM departures 63.9%.
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 | 3,274 | 77.6% | 0.86% | -3 min | 5.6% |
Weekly and seasonal patterns
By day of week
Saturday is historically the most reliable day and Sunday the least, a gap of 13.2 percentage points.
By month
- Jan: 80.4%
- Feb: 79.3%
- Mar: 82.1%
- Apr: 81.5%
- May: 76.8%
- Jun: 70.6%
- Jul: 68.9%
- Aug: 76.5%
- Sep: 79.9%
- Oct: 77.9%
- Nov: 84.0%
- Dec: 80.7%
July is historically the weakest month and November the strongest, a spread of 15.1 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 77.6% against 78.0% in the 12 months before — broadly unchanged.
Data and methodology
Calculated by FlyerIntel from 3,274 SAN → 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