Route reliability record

RNO→DEN

Reno to Denver

Flights: 2,519
Period: July 2025 to June 2026
Distance: 804 mi
Carriers: 4

This route earns a 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 8 points better than the national rate of 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 2,519 flights, of which Southwest Airlines flew 1,088 at 86.7% on time.

Set against the rest of the country, this route's record is 8 points better than the US average of 77.6%. That gap is worth roughly 82 fewer late arrivals for every thousand flights.

On time

85.8%

Arrivals under 15 minutes late, of 2,496 completed flights

Avg delay

73 min

Across delayed arrivals only, not all flights

Cancelled

0.40%

National rate is 1.81%

Best carrier

Southwest

86.7% on time across 1,088 flights

These figures cover 2,519 flights between July 2025 and June 2026. The median arrival is 9 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

Which airline is most reliable on RNO to DEN

The two carriers here are closely matched: 2 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

On-time performance by carrier on RNO to DEN
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlinesthin sample	25	96.0%	23 min	0.00%	A+
Southwest Airlines	1,088	86.7%	63 min	0.28%	A+
United Airlines	1,344	85.0%	77 min	0.52%	A+
Frontier Airlinesthin sample	62	83.9%	137 min	0.00%	B+

No carrier stands out. Southwest tops the table at 86.7%, 2 points clear of the bottom, which is inside the range this kind of sample moves year to year.

Departure window

The best time of day to leave

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 26 points, against 2 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am728 flights93.1%
8am–11am724 flights88.7%
11am–2pm640 flights84.2%
2pm–5pm254 flights66.8%
5pm–8pm173 flights76.6%
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 93.1% of the time, against 66.8% for the afternoon window. That is 26 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 728 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 25 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.

Darker means more delays. Figures are on-time percentages.January best, July worst

July is the worst month at 70.9% on time, 25 points below January, the best at 95.8%. 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. August was the busiest month here, with 259 flights.

Across the week, Saturday is the strongest day at 91.5% on time and Monday the weakest at 82.9%. 9 points is a smaller lever than departure hour, but it is free.

Delay causes

Why this route gets delayed

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 26,000 reported delay minutes.

Late-arriving aircraft
35%
National Airspace System
31%
Carrier
28%
Extreme weather
6%
Security
0%

35% 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 26,000 reported delay minutes here, that single category outweighs weather by 6 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 25,856 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 93.1% on time here.

Cancellations are rare at 0.40%, 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 actually costs

5.2% 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 are the a little over an hour kind, which a normal layover absorbs.

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 74.0% on time across 2,519 flights, 12 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 12 points of difference.

The sample behind these figures is 2,519 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.

What to do with this

Booking this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 95.8% on time and July 70.9%, a swing of 25 points. If the dates move at all, move them out of July before you think about anything else. 2,496 completed flights over 12 months sit behind that.

Common questions

RNO to DEN questions

How often is RNO to DEN delayed?

About one flight in seven arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 14.2% of the 2,519 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.

Which airline is most reliable on RNO to DEN?

Southwest Airlines leads at 86.7% on time across 1,088 flights. United Airlines is at the other end on 85.0%, a gap of 2 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.

What time of day has the fewest delays on RNO to DEN?

The 5am–8am departure window is the strongest at 93.1% on time. The 2pm–5pm window is the weakest at 66.8%, 26 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.

How bad are July delays on RNO to DEN?

July is the weakest month at 70.9% on time, compared with 95.8% in January. Across the year that is 25 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Where to go next

Direction matters. RNO to DEN and DEN to RNO are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.

Key figures