Historical on-time performance
Seattle to Chicago
1,733 miData through May 2026Source: US DOT · BTS
Flights on SEA–MDW arrive on time 79% of the time over the last 12 months.
On-time rate79%arrived within 15 min
p90 delay30 min1 in 10 flights is worse (tail risk)
Cancelled0.5%of scheduled flights
based on 645 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).
By airline
How each carrier compares
- Southwest AirlinesOn-time79%Medianon timep9030 minCancel0.5%Flights645
Why flights run late
Delay causes
- Airline36%
- Weather0%
- Air traffic (NAS)15%
- Late aircraft47%
- Security1%
Most delay minutes here are attributed to Late aircraft.
When flights don't go
Why flights were cancelled
- Airline0%
- Weather67%
- Air traffic (NAS)33%
- Security0%
Most cancellations here are attributed to Weather. Shares are among 3 cancellations with a reported cause (BTS reports causes from June 2003).
Over time
On-time trend
By season
On-time rate by month
When to fly
Best time to fly SEA → MDW
All airlines · rolling 36 months (2023-06 .. 2026-05).
Best time of day
Mornings are the most reliable time of day to fly this route — 91% on time.
- Mornings91% on time · p90 10 min · 928 flights
- Overnights78% on time · p90 30 min · 207 flights
- Middays62% on time · p90 40 min · 517 flights
Best day of week
On-time rates are fairly even by day on this route — ranging from 73% to 82% on time.
- Tuesdays82% on time · p90 25 min · 256 flights
- Wednesdays82% on time · p90 30 min · 256 flights
- Sundays81% on time · p90 30 min · 233 flights
- Mondays80% on time · p90 30 min · 254 flights
- Saturdays80% on time · p90 25 min · 233 flights
- Fridays75% on time · p90 30 min · 254 flights
- Thursdays73% on time · p90 30 min · 254 flights
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