Route reliability record
LAS→COS
Las Vegas to Colorado Springs
- Flights
- 865
- Period
- September 2025 to August 2026
- Distance
- 604 mi
- Carriers
- 1
This route sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.3%. The late ones land roughly 55 minutes behind schedule. That rests on 865 LAS to COS flights, with a median arrival 2 minutes early.
Best time to fly LAS to COS: a 8am–11am departure, ideally on a Tuesday. Flights in that window arrived on time 87.3% of the time and Tuesday flights 86.5%, against 74.4% for the route overall.
The US average over the same twelve months is 77.3%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
74.4%
Arrivals under 15 minutes late, of 861 completed flights
Avg delay
54 min
Across delayed arrivals only, not all flights
Cancelled
0.35%
National rate is 1.89%
Best carrier
Southwest
74.4% on time across 865 flights
These figures cover 865 flights between September 2025 and August 2026. Beyond the headline rate, 8.5% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Which airline is most reliable on LAS to COS
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 |
|---|---|---|---|---|---|
| Southwest Airlines | 865 | 74.4% | 54 min | 0.35% | C+ |
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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 25 points, against half a point between the best and worst carrier.
- 5am–8am25 flights—
- 8am–11am245 flights87.3%
- 11am–2pm26 flights—
- 2pm–5pm170 flights65.9%
- 5pm–8pm126 flights78.6%
- 8pm–5am273 flights62.5%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 62.5% on time, against 87.3% for the 8am–11am 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 8pm–5am window is the busiest, with 273 flights scheduled in it.
Explore
Filter LAS to COS by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On LAS to COS, the best departure window is 8am–11am at 87.3% on time and the worst is 8pm–5am at 62.5%, a wide gap of 24.8 points. All US flights leaving 8am–11am ran 83.9%.
- 5–8am—
- 8–11am87.3%
- 11am–2pm—
- 2–5pm65.9%
- 5–8pm78.6%
- 8pm–5am62.5%
best all US flightsScale 55% to 95%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 27 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.
August is the worst month at 60.3% on time, 27 points below January, the best at 87.1%. 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. May was the busiest month here, with 79 flights.
Across the week, Tuesday is the strongest day at 86.5% on time and Thursday the weakest at 65.0%, a spread of 22 points.
Delay causes
Why this route gets delayed
Late-arriving aircraft accounts for 59% of the 12,000 delay minutes carriers reported here, and the remaining four split what is left.
- 59%Late-arriving aircraft
- 31%Carrier
- 8%National Airspace System
- 1%Extreme weather
- 0%Security
59% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 12,000 reported delay minutes here, that single category outweighs weather by 48 to one. The split is drawn from 11,834 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 87.3% on time here.
Cancellations are rare at 0.35%, 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 actually costs
8.5% 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 roughly 55 minutes, which a normal layover absorbs.
The 604 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 is a different operation and performs like one: it runs 80.0% on time across 865 flights, 6 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 6 points of difference.
One caution: this is a thin sample. 865 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 COS after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 865 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 74.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 861 completed flights over 12 months sit behind that.
Common questions
LAS to COS questions
How often is LAS to COS delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 25.6% of the 865 flights in this analysis, against 22.7% nationally. Delayed flights are late by roughly 55 minutes on average.
How reliable is LAS to COS compared with the rest of the country?
74.4% of flights arrive on time here against a national 77.3%, a difference of 3 points against it. That is worth a C+ on this site's grading scale.
What time of day has the fewest delays on LAS to COS?
The 8am–11am departure window is the strongest at 87.3% on time. The 8pm–5am window is the weakest at 62.5%, 25 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 August delays on LAS to COS?
August is the weakest month at 60.3% on time, compared with 87.1% in January. Across the year that is 27 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
- COS to LAS — the return legseparate record
- Harry Reid International (LAS) delay statistics
- LAS to LAX, a related route77.9%
- DEN to COS, a related route76.5%
- LAS to DEN, a related route76.5%
- Southwest Airlines on-time record74.4%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Direction matters. LAS to COS and COS to LAS 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.