Flight number record
F9 4567
Frontier Airlines · St. Louis to Denver
- Route
- STL → DEN
- Departs
- 20:08
- Flights
- 255
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s F9 4567, check with Frontier Airlines.
F9 4567 sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 255 flights, with a median arrival 7 minutes early.
The national on-time rate over the same period is 77.6%, so F9 4567 runs 4 points behind the country as a whole. Across a thousand flights that is about 42 extra late arrivals.
Key figures
On time
73.4%
Arrivals under 15 minutes late, of 252 completed flights
Avg delay
83 min
Across delayed arrivals only, not all flights
Cancelled
1.18%
National rate is 1.81%
1 hour+ late
11.9%
National rate is 8.1%
These figures cover 255 flights between July 2025 and June 2026. Beyond the headline rate, 11.9% 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 4567 flies
F9 4567 flies STL to DEN without a single fixed slot. Its most common scheduled departure was 20:08, used on 36 of 255 flights, with 19:55 (33 flights) and 19:43 (31 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 20:0836 flights14.1%
- Departs 19:5533 flights12.9%
- Departs 19:4331 flights12.2%
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 20:08 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.5%, and F9 4567 runs 3 points better at 73.4%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
Against the route
F9 4567 next to STL to DEN
Every carrier on STL to DEN combined arrived on time 74.9% of the time across 3,655 flights, so F9 4567 is 2 points behind it. Across its whole network Frontier Airlines managed 73.2%, close to this flight's figure.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| F9 4567thin sample | 255 | 73.4% | 83 min | 1.18% | C |
| All Frontier Airlines on STL–DENthin sample | 277 | 74.5% | 83 min | 1.08% | C |
| All carriers on STL–DEN | 3,655 | 74.9% | 70 min | 0.41% | C+ |
| Frontier Airlines, whole network | 205,332 | 73.2% | 84 min | 1.85% | C |
Across the year
F9 4567 quarter by quarter
F9 4567 did not run the same all year. Its best quarter was Oct–Dec 2025 at 84.6% on time and its weakest Jan–Mar 2026 at 61.3%, a swing of 23 points on roughly 64 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 202571 flights71.4%
- Oct–Dec 202579 flights84.6%
- Jan–Mar 202631 flights61.3%
- Apr–Jun 202674 flights68.5%
Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.
By weekday, F9 4567 did best on Wednesday at 78.6% on time and worst on Friday at 54.2%. Each day rests on about 36 flights, so a gap of 24 points is worth noticing but could still narrow in another year.
Delay causes
Why F9 4567 runs late
One category carries most of the weight here. Late-arriving aircraft accounts for 55% of the 5,536 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.
- 55%Late-arriving aircraft
- 28%National Airspace System
- 16%Carrier
- 1%Extreme weather
55% 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 5,536 reported delay minutes here, that single category outweighs weather by 55 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 5,536 delay minutes reported on F9 4567.
Cancellations sit at 1.18% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
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. 11.9% 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 770 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 255 flights under F9 4567 in the data flew STL 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. 255 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 4567
For a booking, read F9 4567 as 73.4% on time with 1.18% cancelled over 255 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- STL to DEN, every carrier and departure
- DEN to STL, the return direction
- St. Louis Lambert International (STL) 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.