Route · SEA → MDW · 2020–2025 BTS data
Seattle to Chicago
According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), SEA to MDW (Seattle to Chicago) ranks #3250 of 4927 tracked domestic routes by total flights (most flights = #1).
Data updated 2026-06-13
- 83.8%
- On-time
- +4.8 pts
- vs US avg
- 50 min
- Delay when late
- 3,126
- Flights
- #3250 of 4927
- Corpus placement
Cancelled
0.2%
Best Month
Jun 2025 74%
Worst Month
Jul 2024 65%
Distance
1,733 mi
Carriers
1
Monthly Performance
Recent 24 months of route data.
| Period | Flights | Delayed | Cancelled | Diverted | Carriers |
|---|---|---|---|---|---|
| Dec 2025 | 31 | 2 | 0 | 0 | WN |
| Nov 2025 | 30 | 2 | 0 | 1 | WN |
| Oct 2025 | 33 | 1 | 0 | 0 | WN |
| Sep 2025 | 86 | 26 | 0 | 0 | WN |
| Aug 2025 | 88 | 28 | 0 | 0 | WN |
| Jul 2025 | 88 | 28 | 1 | 2 | WN |
| Jun 2025 | 78 | 20 | 0 | 0 | WN |
| May 2025 | 31 | 2 | 0 | 0 | WN |
| Apr 2025 | 30 | 0 | 0 | 0 | WN |
| Mar 2025 | 31 | 3 | 0 | 0 | WN |
| Jan 2025 | 31 | 2 | 0 | 0 | WN |
| Dec 2024 | 31 | 0 | 0 | 0 | WN |
| Nov 2024 | 30 | 0 | 0 | 0 | WN |
| Oct 2024 | 35 | 4 | 0 | 0 | WN |
| Sep 2024 | 85 | 29 | 0 | 0 | WN |
| Aug 2024 | 88 | 28 | 0 | 2 | WN |
| Jul 2024 | 88 | 31 | 0 | 0 | WN |
| Jun 2024 | 80 | 26 | 0 | 0 | WN |
| May 2024 | 31 | 3 | 0 | 0 | WN |
| Apr 2024 | 30 | 3 | 0 | 0 | WN |
| Mar 2024 | 31 | 0 | 0 | 1 | WN |
| Jan 2024 | 31 | 5 | 1 | 0 | WN |
| Dec 2023 | 31 | 7 | 0 | 0 | WN |
| Nov 2023 | 30 | 3 | 0 | 0 | WN |
SEA–MDW seasonal on-time pattern
Best: February (95.9%) · weakest: August (76.6%)
Strongest calendar month
February
95.9% on-time · ~49 flights/mo
Busiest calendar month
July
~74 flights/mo avg
Weakest calendar month
August
76.6% on-time · ~74 flights/mo
Cancellation Rate
0.2%
2 of 1,178 flights
Diversion Rate
0.5%
6 of 1,178 flights
Explore origin & destination
On-time and delay data for the airports this route connects.
SEA - Seattle
Full on-time, delay-cause, and seasonal performance for Seattle, WA.
SEA on-time profileMDW - Chicago
Full on-time, delay-cause, and seasonal performance for Chicago, IL.
MDW on-time profileCompare the two airports
See SEA and MDW side by side on delays, cancellations, and reliability.
Compare SEA vs MDWOrigin-hub reliability standing
Mid-pack among SEA departures
From SEA, this corridor sits with 63 other 75–85% on-time routes out of 89 tracked departures, not the hub's reliability leaders (25 at ≥85%) and not the softest ( 1 below 75%). Destination: Chicago · fleet on-time rank #1669 of 4927.
Similar routes
Other BTS-tracked routes with comparable performance or trip length to SEA–MDW.
Routes with a similar on-time rate
What the Data Says About SEA to MDW
Bureau of Transportation Statistics records show Seattle to Chicago (SEA to MDW) running a 83.8% on-time rate over 3,126 tracked flights, on the stronger end of a typical domestic pairing. When flights do run late, the average delay is 49.8 minutes. The 1,733-mile corridor is served by 1 carrier, and over the last 24 months 0.2% of 1,178 flights were cancelled, 0.5% diverted.
Monthly performance varies moderately here: Jun 2025 was the strongest month at 74% on-time versus Jul 2024 at 65%, a 10-point difference.
On the multi-year calendar, SEA–MDW peaks in February at 95.9% on-time while July carries the heaviest traffic (~74 flights per month) ; the softest month is August at 76.6%, a 19.3-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.
Frequently Asked Questions
Where does SEA to MDW rank among US routes by traffic? ▼
How often are flights delayed from SEA to MDW? ▼
What is the cancellation rate for SEA to MDW? ▼
How far is the flight from SEA to MDW? ▼
When is the best time to fly from SEA to MDW? ▼
Airports on this route
Data source
Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.
Read our methodology - how this data is sourced, computed, and verified.
Using SEA–MDW data
SEA–MDW runs 4.8 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.
- Compare SEA and MDW airport profiles: delay causes and top routes differ even on the same corridor. SEA airport
- If your dates flex, February (95.9% on-time) beats August (76.6%) on this corridor. Seasonal chart
- 4 other routes post a similar 83.8% on-time rate; compare before you commit to this pairing. Similar routes
On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.
Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.