Carrier route record
WNDEN→EUG
Southwest Airlines · Denver to Eugene
- Flights
- 428
- Period
- July 2025 to June 2026
- Share of route
- 34%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on DEN to EUG sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 8 points worse than the national rate of 77.6%. The late ones land about 55 minutes behind schedule. That rests on 428 flights, with a median arrival 1 minute late.
The national on-time rate over the same period is 77.6%, so Southwest on DEN to EUG runs 8 points behind the country as a whole. Across a thousand flights that is about 78 extra late arrivals.
Key figures
On time
69.8%
Arrivals under 15 minutes late, of 427 completed flights
Avg delay
55 min
Across delayed arrivals only, not all flights
Cancelled
0.23%
National rate is 1.81%
Whole route
73.5%
Every carrier on DEN to EUG, 1,272 flights
These figures cover 428 flights between July 2025 and June 2026. Beyond the headline rate, 8.9% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Southwest against every carrier on DEN to EUG
Southwest flew 428 of the 1,272 flights on DEN to EUG, about 34% of it. Its 69.8% on time is 4 points worse than the route as a whole, which runs 73.5%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from SkyWest at 95.7% to Southwest at 69.8%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 116 | 95.7% | 60 min | 0.00% | A+ |
| United Airlines | 728 | 72.1% | 56 min | 0.14% | C+ |
| Southwest Airlines (this page) | 428 | 69.8% | 55 min | 0.23% | C+ |
Departure window
When Southwest runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 38 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am1 flights—
- 8am–11am147 flights82.3%
- 11am–2pm113 flights83.2%
- 2pm–5pm34 flights66.7%
- 5pm–8pm—
- 8pm–5am133 flights45.1%
Scale runs 35% to 90%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 45.1% on time, against 83.2% for the 11am–2pm slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8am–11am window is the busiest, with 147 flights scheduled in it.
Across the year
Southwest on DEN to EUG through the year
- Jul–Sep 202589 flights70.5%
- Oct–Dec 202587 flights81.6%
- Jan–Mar 202680 flights63.8%
- Apr–Jun 2026172 flights66.3%
Scale runs 55% to 85%. Rows with fewer than 30 flights show a dash.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 69.8% on time across 428 flights.
Southwest on DEN to EUG did not run the same all year. Its best quarter was Oct–Dec 2025 at 81.6% on time and its weakest Jan–Mar 2026 at 63.8%, a swing of 18 points on roughly 107 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
Across the week, Monday is the strongest day at 74.2% on time and Saturday the weakest at 65.9%. 8 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Southwest runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 59% of the 7,029 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 59%Late-arriving aircraft
- 30%Carrier
- 10%National Airspace System
59% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 7,029 reported delay minutes here, that single category outweighs weather by 59 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 7,029 reported delay minutes.
Cancellations are rare at 0.23%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
8.9% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about 55 minutes, which a normal layover absorbs.
The 996 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 72.8% on time across 427 flights, 3 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 3 points of difference.
One caution: this is a thin sample. 428 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Southwest on DEN to EUG
Put together: treat all of this as provisional. 428 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 69.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 427 completed flights over 12 months sit behind that.
Related
Where to go next
- DEN to EUG, every carrier
- Southwest on EUG to DEN, the return leg
- SkyWest Airlines on DEN to EUG95.7%
- United Airlines on DEN to EUG72.1%
- Southwest Airlines network-wide record
- Denver International (DEN) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.