Route profile
MDW→SFO
Flight reliability, delays and best times to fly from Chicago to San Francisco, 1,855 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 1% of comparable major US routes (4,598 compared)
Calculated from 1,246 flights. How this is calculated · What counts as on time
MDW → SFO arrives on time 56.3% of the time; the return trip, SFO → MDW, arrives on time 74.8% of the time, an 18.4-point gap between the two directions of the same city pair.
MDW → SFO spends 25.3 minutes on the ground on a 1,855-mile trip: 16.4 minutes from pushback to wheels-up at MDW and 8.9 minutes from touchdown to gate at SFO.
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 99% of 5,368 comparable routes.
48.2% on time over the most recent 12 months (2025-08 to 2026-07), against 67.5% in the 12 months before (2024-08 to 2025-07), a change of 19.3 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 MDW to SFO differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
MDW to SFO struggles most at 10 AM: 34.8% of its flights scheduled then arrive on time, 44.5 points behind the 79.3% on routes of similar length at the same hour. Against all other routes the gap is 47.9 points.
Wednesday is the day MDW to SFO slips furthest against routes of similar length, 50.0% on time where they average 80.6%, 30.6 points lower. Against all other routes the gap is 30.8 points.
In June, MDW to SFO runs 32.5 points below routes of similar length, 40.1% on time to 72.6%. Against all other routes the gap is 32.6 points.
Southwest Airlines’ flights on MDW to SFO arrive on time 56.8% of the time, 18.5 points below the 75.3% it manages on its routes of similar length. Against all other routes the gap is 20.6 points.
MDW to SFO against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 10 AM departures | 34.8% | routes of similar length | 79.3% | −44.5 pts | 158 here, 71,196 there |
| Weekday: Wednesday | 50.0% | routes of similar length | 80.6% | −30.6 pts | 168 here, 168,425 there |
| Month: June | 40.1% | routes of similar length | 72.6% | −32.5 pts | 152 here, 108,757 there |
| Airline: Southwest Airlines | 56.8% | routes of similar length | 75.3% | −18.5 pts | 962 here, 191,993 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 1,855 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
72 min late
against a median of 9 min late
MDW → SFO has an average that understates its risk: a typical arrival is 9 min late, but the worst tenth are 63 minutes worse than that. If the trip has something unmissable at the end of it, the median is the wrong number to plan against.
Percentiles over 1,246 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SFO after arriving from MDW.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 64% | Likely to miss |
| 45 min | 43% | Likely to miss |
| 60 min | 30% | High risk |
| 90 min | 14% | Some risk |
| 120 min | 6.6% | Some 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 1.20% 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 1,227 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 72 minutes late (90th-percentile gate arrival delay), over 1,246 operations.
Any other layover length: connection checker.
Best time to fly
MDW → SFO flights departing 5–9 AM arrived on time 76.2% of the time, against 42.4% for 9 PM–5 AM departures, a gap of 33.8 percentage points.
By departure window
By departure hour
- 12 AM to 8 AM: too few flights to score
- 9 AM: 69.2% on time from 156 flights
- 10 AM: 34.8% on time from 159 flights
- 11 AM to 8 PM: too few flights to score
- 9 PM: 42.5% on time from 158 flights
- 10 PM to 11 PM: too few flights to score
Why MDW → SFO runs late
July 2023 – July 2026
airspace and airport capacity, including weather-driven flow control
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for MDW → SFO. Only delays of 15 minutes or more are attributed. What the five causes mean
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 | 972 | 56.8% | 0.82% | 9 min | 13.0% |
| Frontier Airlines | 274 | 54.7% | 2.55% | 9 min | 17.0% |
Southwest Airlines flew 78.0% of the 1,246 flights listed. Frontier Airlines cancelled 2.55% of its flights here against 0.82% for Southwest Airlines.
Southwest Airlines arrived on time 2.1 percentage points more often than Frontier Airlines on this route.
Other ways to fly Chicago to San Francisco
Airport pairs in the same two city markets, as the DOT defines them.
| Route | Flights | On time | Cancelled | Median delay | Score |
|---|---|---|---|---|---|
| ORD→SFO Chicago to San Francisco | 16,116 | 71.8% | 1.14% | -3 min | 53 |
| MDW→SFO this route Chicago to San Francisco | 1,246 | 56.3% | 1.20% | 9 min | 30 |
ORD → SFO is the most reliable pairing for this journey at 71.8% on time, against 56.3% for MDW → SFO.
Flying to SFO from the Chicago area? Compare MDW, ORD for SFO, with the same test for what counts as a real difference.
Weekly and seasonal patterns
By day of week
Saturday is historically the most reliable day and Friday the least, a gap of 13.8 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 48.2% against 67.5% in the 12 months before — declining by 19.3 percentage points.
Data and methodology
Calculated by FlyerIntel from 1,246 MDW → SFO 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