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DelayAtlas

Carrier route record

WNRNODEN

Southwest Airlines · Reno to Denver

Flights
1,088
Period
July 2025 to June 2026
Share of route
43%
Carriers
4
A+GRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.

Southwest on RNO to DEN earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 1,088 flights, with a median arrival 7 minutes early.

Set against the rest of the country, Southwest's RNO to DEN record is 9 points better than the US average of 77.6%. That gap is worth roughly 91 fewer late arrivals for every thousand flights.

Key figures

On time

86.7%

Arrivals under 15 minutes late, of 1,079 completed flights

Avg delay

63 min

Across delayed arrivals only, not all flights

Cancelled

0.28%

National rate is 1.81%

Whole route

85.8%

Every carrier on RNO to DEN, 2,519 flights

These figures cover 1,088 flights between July 2025 and June 2026. The median arrival is 7 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.

Carrier by carrier

Southwest against every carrier on RNO to DEN

Southwest flew 1,088 of the 2,519 flights on RNO to DEN, about 43% of it. Its 86.7% on time is about level with the route as a whole at 85.8%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from SkyWest at 96.0% to Frontier at 83.9%. Two 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.

On-time performance by carrier on RNO to DEN
AirlineFlightsOn timeAvg delayCancelledGrade
SkyWest Airlinesthin sample2596.0%23 min0.00%A+
Southwest Airlines (this page)1,08886.7%63 min0.28%A+
United Airlines1,34485.0%77 min0.52%A+
Frontier Airlinesthin sample6283.9%137 min0.00%B+

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 28 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–8am364 flights94.5%
  • 8am–11am337 flights91.9%
  • 11am–2pm128 flights89.8%
  • 2pm–5pm254 flights66.8%
  • 5pm–8pm5 flights
  • 8pm–5am

Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 94.5% of the time, against 66.8% for the afternoon window. That is 28 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 364 flights scheduled in it.

Across the year

Southwest on RNO to DEN through the year

On-time rate by calendar month98J85F90M90A87M80J71J87A85S86O94N89D
Darker means more delays. Figures are on-time percentages.January best, July worst

July is the worst month at 70.8% on time, 27 points below January, the best at 97.8%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. July was the busiest month here, with 97 flights.

Across the week, Saturday is the strongest day at 91.8% on time and Thursday the weakest at 79.7%. 12 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week83.9Mon91.1Tue89.1Wed79.7Thu81.7Fri91.8Sat89.2Sun
Monday: 83.9 percent on time. Tuesday: 91.1 percent on time. Wednesday: 89.1 percent on time. Thursday: 79.7 percent on time. Friday: 81.7 percent on time. Saturday: 91.8 percent on time. Sunday: 89.2 percent on time

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 9,093 reported delay minutes.

  • Late-arriving aircraft
    36%
  • National Airspace System
    35%
  • Carrier
    17%
  • Extreme weather
    11%
  • Security
    0%

Extreme weather accounts for 11% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 1.8 times the usual weather exposure. The split is drawn from 9,093 reported delay minutes.

36% 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 9,093 reported delay minutes here, that single category outweighs weather by 3 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.

Cancellations are rare at 0.28%, 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

Badly late arrivals are rare here: only 4.9% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

The 804 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 69.8% on time across 1,087 flights, 17 points below 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 17 points of difference.

One caution: this is a thin sample. 1,088 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 RNO to DEN

Put together: treat all of this as provisional. 1,088 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 86.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,079 completed flights over 12 months sit behind that.

Related

Where to go next

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.