Flight number record
F9 3540
Frontier Airlines · Las Vegas to Denver
- Route
- LAS → DEN
- Departs
- 14:49
- Flights
- 251
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s F9 3540, check with Frontier Airlines.
F9 3540 draws a C+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is close to two hours behind schedule. Build slack into anything you connect to. That rests on 251 flights, with a median arrival 1 minute early.
The national on-time rate over the same period is 77.6%, so F9 3540 runs 10 points behind the country as a whole. Across a thousand flights that is about 104 extra late arrivals.
Key figures
On time
67.2%
Arrivals under 15 minutes late, of 250 completed flights
Avg delay
108 min
Across delayed arrivals only, not all flights
Cancelled
0.40%
National rate is 1.81%
1 hour+ late
17.6%
National rate is 8.1%
These figures cover 251 flights between July 2025 and June 2026. Beyond the headline rate, 17.6% 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.
Schedule
When F9 3540 flies
F9 3540 flies LAS to DEN without a single fixed slot. Its most common scheduled departure was 14:49, used on 35 of 251 flights, with 15:46 (26 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 14:4935 flights13.9%
- Departs 15:4626 flights10.4%
Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 14:49 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 72.4%, and F9 3540 runs 5 points worse at 67.2%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
Against the route
F9 3540 next to LAS to DEN
Every carrier on LAS to DEN combined arrived on time 77.0% of the time across 7,088 flights, so F9 3540 is 10 points behind it. Frontier flew 1,554 flights on the same city pair under all its flight numbers, including this one, and those ran 79.1% on time. Across its whole network Frontier Airlines managed 73.2%, which this flight trails by 6 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| F9 3540thin sample | 251 | 67.2% | 108 min | 0.40% | C+ |
| All Frontier Airlines on LAS–DEN | 1,554 | 79.1% | 90 min | 0.97% | B+ |
| All carriers on LAS–DEN | 7,088 | 77.0% | 66 min | 0.87% | B+ |
| Frontier Airlines, whole network | 205,332 | 73.2% | 84 min | 1.85% | C |
Across the year
F9 3540 quarter by quarter
F9 3540 did not run the same all year. Its best quarter was Jan–Mar 2026 at 78.9% on time and its weakest Jul–Sep 2025 at 54.3%, a swing of 25 points on roughly 63 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.
- Jul–Sep 202570 flights54.3%
- Oct–Dec 202535 flights65.7%
- Jan–Mar 202658 flights78.9%
- Apr–Jun 202688 flights70.5%
Scale runs 45% to 85%. Rows with fewer than 30 flights show a dash.
By weekday, F9 3540 did best on Saturday at 82.4% on time and worst on Friday at 50.0%. Each day rests on about 36 flights, so a gap of 32 points is worth noticing but could still narrow in another year.
Delay causes
Why F9 3540 runs late
One category carries most of the weight here. Late-arriving aircraft accounts for 47% of the 8,836 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.
- 47%Late-arriving aircraft
- 34%National Airspace System
- 19%Carrier
47% 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 8,836 reported delay minutes here, that single category outweighs weather by 47 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 8,836 delay minutes reported on F9 3540.
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 routes
What a delay on this flight costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 17.6% 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.
The 628 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.
Every one of the 251 flights under F9 3540 in the data flew LAS to DEN. The number was not reused on any other city pair, which makes this a clean record of one route.
One caution: this is a thin sample. 251 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 F9 3540
For a booking, F9 3540 is a flight to put a long connection behind. 17.6% of its completed flights arrived an hour or more late, which a short layover will not absorb. If the onward flight is on a separate ticket, the risk sits with you.
Related
Where to go next
- LAS to DEN, every carrier and departure
- DEN to LAS, the return direction
- United Airlines 596 on the same route97.2%
- Frontier Airlines 1994 on the same route84.0%
- United Airlines 2108 on the same route70.2%
- Frontier Airlines 4612 on the same route71.1%
- Frontier Airlines 2350 on the same route86.3%
- Harry Reid International (LAS) delay statistics
- Denver International (DEN) delay statistics
- Frontier Airlines on-time record
- Every Frontier Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means Frontier Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
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.