Carrier route record
WNEUG→DEN
Southwest Airlines · Eugene to Denver
- Flights
- 488
- Period
- September 2025 to August 2026
- Share of route
- 38%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on EUG to DEN sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.3%. The late ones land about an hour behind schedule. That rests on 488 flights, with a median arrival right on schedule.
The national on-time rate over the same period is 77.3%, so Southwest on EUG to DEN runs 4 points behind the country as a whole. Across a thousand flights that is about 42 extra late arrivals.
Key figures
On time
73.1%
Arrivals under 15 minutes late, of 484 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
0.20%
National rate is 1.89%
Whole route
79.9%
Every carrier on EUG to DEN, 1,270 flights
These figures cover 488 flights between September 2025 and August 2026. Beyond the headline rate, 8.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Southwest against every carrier on EUG to DEN
Southwest flew 488 of the 1,270 flights on EUG to DEN, about 38% of it. Its 73.1% on time is 7 points worse than the route as a whole, which runs 79.9%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from SkyWest at 87.0% to Southwest at 73.1%. 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 | 54 | 87.0% | 68 min | 0.00% | A+ |
| United Airlines | 728 | 83.9% | 92 min | 0.41% | B+ |
| Southwest Airlines (this page) | 488 | 73.1% | 59 min | 0.20% | C+ |
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 45 points, against half a point between the best and worst carrier.
- 5am–8am178 flights93.2%
- 8am–11am—
- 11am–2pm162 flights73.3%
- 2pm–5pm148 flights48.6%
- 5pm–8pm—
- 8pm–5am—
Scale runs 40% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 93.2% of the time, against 48.6% for the afternoon window. That is 45 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 178 flights scheduled in it.
Across the year
Southwest on EUG to DEN through the year
- Jul–Sep 202526 flights—
- Oct–Dec 202587 flights70.9%
- Jan–Mar 202679 flights88.5%
- Apr–Jun 2026172 flights69.6%
- Jul–Sep 2026124 flights70.7%
Scale runs 60% to 95%. 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 73.1% on time across 488 flights.
Southwest on EUG to DEN did not run the same all year. Its best quarter was Jan–Mar 2026 at 88.5% on time and its weakest Apr–Jun 2026 at 69.6%, a swing of 19 points on roughly 122 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, Tuesday is the strongest day at 77.9% on time and Friday the weakest at 66.7%, a spread of 11 points.
Arrival by arrival
How late Southwest on EUG to DEN runs when it is late
The 130 late arrivals split 41 under half an hour, 50 between 30 and 60 minutes, and 39 an hour or more.
- 15+ min early88 flights18.2%
- Within 15 min266 flights55.0%
- 15–29 min late41 flights8.5%
- 30–59 min late50 flights10.3%
- 1–2 hours late29 flights6.0%
- 2+ hours late10 flights2.1%
Scale runs 0% to 100%.
Share of 484 completed flights by arrival against schedule.
24 of 138 late departures made up the time and arrived on time, 17% of them. 16 flights left on time and still arrived late.
The worst days
Worst days for Southwest on EUG to DEN
The latest arrival of the period was on 18 December 2025, 9 hours 2 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 18 December 2025 | 9 hours 2 minutes | Carrier |
| 9 April 2026 | 5 hours 59 minutes | National Airspace System |
| 21 June 2026 | 5 hours 37 minutes | Carrier |
| 17 May 2026 | 3 hours 43 minutes | Carrier |
| 17 February 2026 | 2 hours 48 minutes | National Airspace System |
Delay causes
Why Southwest runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 7,691 reported delay minutes.
- 34%National Airspace System
- 29%Carrier
- 27%Late-arriving aircraft
- 9%Extreme weather
34% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 2,642 minutes out of 7,691, against a national NAS share of 21%. The split is drawn from 7,691 reported delay minutes.
Cancellations are rare at 0.20%, below the national 1.89% 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
8.1% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, 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.
The return leg runs 71.0% on time across 489 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 488 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 EUG to DEN
Put together: treat all of this as provisional. 488 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 73.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 484 completed flights over 12 months sit behind that.
Related
Where to go next
- EUG to DEN, every carrier
- Southwest on DEN to EUG, the return leg
- United Airlines on EUG to DEN83.9%
- Southwest Airlines network-wide record
- Denver International (DEN) delay statistics
- The best time of day to fly, according to 7.05 million flight records
- Connecting flights: how much buffer the data says you need
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.