Route reliability record
RIW→DEN
Riverton to Denver
- Flights
- 728
- Period
- July 2025 to June 2026
- Distance
- 296 mi
- Carriers
- 1
This route lands a B+, 5 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about 2.3 hours on average. That is a workable record, not a spotless one. That rests on 728 RIW to DEN flights, with a median arrival 11 minutes early.
Set against the rest of the country, this route's record is 5 points better than the US average of 77.6%. That gap is worth roughly 45 fewer late arrivals for every thousand flights.
Key figures
On time
82.1%
Arrivals under 15 minutes late, of 720 completed flights
Avg delay
135 min
Across delayed arrivals only, not all flights
Cancelled
0.41%
National rate is 1.81%
Best carrier
SkyWest
82.1% on time across 728 flights
These figures cover 728 flights between July 2025 and June 2026. Beyond the headline rate, 10.1% 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
Which airline is most reliable on RIW to DEN
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 Airlines | 728 | 82.1% | 135 min | 0.41% | B+ |
Flight by flight
Flights on RIW to DEN
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Departure window
The best time of day to leave
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 728 flights.
- 5am–8am363 flights85.6%
- 8am–11am1 flights—
- 11am–2pm—
- 2pm–5pm364 flights78.5%
- 5pm–8pm—
- 8pm–5am—
Scale runs 70% to 90%. Rows with fewer than 30 flights show a dash.
The early departures do better, though not dramatically: 85.6% on time for the 5am–8am window against 78.5% for 2pm–5pm. Worth taking if the schedule allows, not worth an extra connection. The 2pm–5pm window is the busiest, with 364 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 28 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.
June is the worst month at 70.0% on time, 28 points below September, the best at 98.3%. 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. January was the busiest month here, with 62 flights.
Across the week, Wednesday is the strongest day at 86.3% on time and Saturday the weakest at 74.8%. 12 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Carrier accounts for 56% of the 17,000 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.
- 56%Carrier
- 25%Late-arriving aircraft
- 10%Extreme weather
- 9%National Airspace System
- 0%Security
The largest share of delay minutes, 56%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 9,682 of the 17,000 delay minutes reported here. The split is drawn from 17,413 reported delay minutes.
Cancellations are rare at 0.41%, 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
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.1% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
At 296 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.
The return leg runs 81.7% on time across 728 flights, within half a point 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. 728 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.
Work out the risk of missing a connection in DEN after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 728 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 82.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 720 completed flights over 12 months sit behind that.
Common questions
RIW to DEN questions
How often is RIW to DEN delayed?
About one flight in six arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 17.9% of the 728 flights in this analysis, against 22.4% nationally. Delayed flights are late by about 2.3 hours on average.
How reliable is RIW to DEN compared with the rest of the country?
82.1% of flights arrive on time here against a national 77.6%, a difference of 5 points in its favour. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on RIW to DEN?
The 5am–8am departure window is the strongest at 85.6% on time. The 2pm–5pm window is the weakest at 78.5%, 7 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 June delays on RIW to DEN?
June is the weakest month at 70.0% on time, compared with 98.3% in September. Across the year that is 28 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- DEN to RIW — the return legseparate record
- Denver International (DEN) delay statistics
- PHX to DEN, a related route77.2%
- SLC to DEN, a related route77.8%
- LAX to DEN, a related route81.7%
- SkyWest Airlines on-time record82.1%
- How often a connection fails at the major US hubs
- Connecting flights: how much buffer the data says you need
Direction matters. RIW to DEN and DEN to RIW are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.