Flight number record
F9 1821
Frontier Airlines · Cleveland to Las Vegas
- Route
- CLE → LAS
- Departs
- 21:43
- Flights
- 322
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s F9 1821, check with Frontier Airlines.
F9 1821 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 77.3%. The late ones land an hour and a half behind schedule. That rests on 322 flights, with a median arrival 7 minutes early.
Key figures
On time
73.7%
Arrivals under 15 minutes late, of 319 completed flights
Avg delay
92 min
Across delayed arrivals only, not all flights
Cancelled
0.93%
National rate is 1.89%
1 hour+ late
12.9%
National rate is 8.3%
These figures cover 322 flights between September 2025 and August 2026. Beyond the headline rate, 12.9% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When F9 1821 flies
F9 1821 flies CLE to LAS without a single fixed slot. Its most common scheduled departure was 21:43, used on 49 of 322 flights, with 20:50 (33 flights) next.
- Departs 21:4349 flights15.2%
- Departs 20:5033 flights10.2%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 21:43 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.1%, and F9 1821 runs 4 points better at 73.7%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
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Against the route
F9 1821 next to CLE to LAS
Every carrier on CLE to LAS combined arrived on time 75.7% of the time across 1,001 flights, so F9 1821 is 2 points behind it. Frontier flew 634 flights on the same city pair under all its flight numbers, including this one, and those ran 73.5% on time. Across its whole network Frontier Airlines managed 72.7%, close to this flight's figure.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| F9 1821thin sample | 322 | 73.7% | 92 min | 0.93% | C+ |
| All Frontier Airlines on CLE–LAS | 634 | 73.5% | 89 min | 2.52% | C |
| All carriers on CLE–LAS | 1,001 | 75.7% | 77 min | 1.80% | B |
| Frontier Airlines, whole network | 213,022 | 72.7% | 84 min | 2.05% | C |
Across the year
F9 1821 quarter by quarter
F9 1821 did not run the same all year. Its best quarter was Jul–Sep 2025 at 86.7% on time and its weakest Jan–Mar 2026 at 61.2%, a swing of 26 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 202530 flights86.7%
- Oct–Dec 202571 flights74.6%
- Jan–Mar 202668 flights61.2%
- Apr–Jun 202691 flights76.7%
- Jul–Sep 202662 flights75.4%
Scale runs 55% to 90%.
By weekday, F9 1821 did best on Wednesday at 83.3% on time and worst on Sunday at 63.8%. Each day rests on about 46 flights, so a gap of 20 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late F9 1821 runs when it is late
F9 1821 often beats the schedule: 108 of 319 completed flights, 34%, arrived 15 minutes or more early. The 84 late arrivals split 20 under half an hour, 23 between 30 and 60 minutes, and 41 an hour or more.
- 15+ min early108 flights33.9%
- Within 15 min127 flights39.8%
- 15–29 min late20 flights6.3%
- 30–59 min late23 flights7.2%
- 1–2 hours late21 flights6.6%
- 2+ hours late20 flights6.3%
Scale runs 0% to 100%.
Share of 319 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 81 departures that left 15 minutes late or more, only 9 made it up before arrival. 12 flights left on time and still arrived late.
The worst days
Worst days for F9 1821
The latest arrival of the period was on 6 April 2026, 11 hours 22 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 6 April 2026 | 11 hours 22 minutes | Late-arriving aircraft |
| 3 November 2025 | 6 hours | Late-arriving aircraft |
| 27 October 2025 | 5 hours 46 minutes | Late-arriving aircraft |
| 16 March 2026 | 5 hours 37 minutes | Late-arriving aircraft |
| 7 September 2025 | 4 hours 31 minutes | Carrier |
Delay causes
Why F9 1821 runs late
Late-arriving aircraft accounts for 55% of the 7,733 delay minutes carriers reported here, and the remaining four split what is left.
- 55%Late-arriving aircraft
- 29%Carrier
- 16%National Airspace System
- 0%Extreme weather
55% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 7,733 reported delay minutes here, that single category outweighs weather by 55 to one. The split is drawn from 7,733 delay minutes reported on F9 1821.
Cancellations sit at 0.93% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
12.9% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
At 1,824 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
Every one of the 322 flights under F9 1821 in the data flew CLE to LAS. 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. 322 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 1821
For a booking, F9 1821 is a flight to put a long connection behind. 12.9% 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
- CLE to LAS, every carrier and departure
- LAS to CLE, the return direction
- Frontier Airlines 3231 on the same route73.6%
- Cleveland Hopkins International (CLE) delay statistics
- Harry Reid International (LAS) 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.