Carrier performance at one airport
F9→DEN
Frontier Airlines at Denver International
- Departures
- 22,870
- Period
- September 2025 to August 2026
- Routes
- 25
- Rank here
- #4 of 9
Frontier Airlines at Denver lands a B+, about a point better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That rests on 22,870 flights, of which Delta Air Lines flew 11,497 at 83.1% on time.
Measured against the airport rather than the country, Frontier Airlines runs 2 points ahead of the 76.7% weighted average across all carriers at DEN. That is the comparison worth making: every operator here works the same runways, the same airspace and the same weather.
Key figures
On time
78.5%
22,662 completed departures
Avg delay
68 min
Across delayed flights only
Cancelled
0.77%
At DEN, this carrier only
Rank here
#4
Of 9 carriers clearing the floor at DEN
These figures cover 23,000 flights between September 2025 and August 2026. The median arrival is 9 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Against the competition
Every carrier at DEN, ranked
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 83.1% of the time; JetBlue Airways manages 65.7%. Sample sizes sit next to every figure, because a two-point gap across 1,258 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 11,497 | 83.1% | 75 min | 1.37% | B |
| SkyWest Airlines | 75,223 | 80.4% | 78 min | 1.09% | B |
| United Airlines | 107,895 | 78.9% | 65 min | 0.41% | B+ |
| Frontier Airlines (this page) | 22,870 | 78.5% | 68 min | 0.77% | B+ |
| Alaska Airlines | 2,879 | 78.1% | 57 min | 0.66% | B+ |
| American Airlines | 8,936 | 77.1% | 105 min | 1.97% | B |
| Allegiant Air | 373 | 76.5% | 94 min | 0.54% | B+ |
| Southwest Airlines | 88,424 | 69.5% | 54 min | 0.72% | C+ |
| JetBlue Airways | 1,258 | 65.7% | 93 min | 4.61% | C− |
JetBlue Airways cancels 4.6% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.
Route by route
Where Frontier Airlines flies from DEN
Frontier Airlines operates 25 routes out of DEN with enough volume to report. Route records inside one carrier at one airport still spread widely, because a short shuttle and a transcontinental have very different exposure to a late inbound.
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DEN to LAS · Las Vegas | 1,626 | 75.8% | 78 min | 1.05% | B |
| DEN to PHX · Phoenix | 1,499 | 77.0% | 70 min | 0.80% | B+ |
| DEN to DFW · Dallas-Fort Worth | 1,200 | 76.0% | 71 min | 0.92% | B+ |
| DEN to SLC · Salt Lake City | 1,033 | 81.9% | 57 min | 0.29% | B+ |
| DEN to DCA · Washington | 983 | 77.5% | 72 min | 0.81% | B+ |
| DEN to MCO · Orlando | 899 | 74.6% | 68 min | 0.89% | C+ |
| DEN to IAH · Houston | 834 | 79.3% | 58 min | 0.48% | B+ |
| DEN to ATL · Atlanta | 801 | 75.5% | 62 min | 0.87% | B+ |
| DEN to LAX · Los Angeles | 797 | 83.4% | 68 min | 0.75% | B+ |
| DEN to SAN · San Diego | 701 | 80.1% | 66 min | 1.43% | B |
| DEN to SFO · San Francisco | 667 | 64.0% | 60 min | 1.05% | D |
| DEN to MSP · Minneapolis | 642 | 74.6% | 70 min | 0.62% | C+ |
| DEN to TPA · Tampa | 621 | 80.5% | 83 min | 0.97% | B+ |
| DEN to AUS · Austin | 607 | 71.3% | 68 min | 0.49% | C+ |
| DEN to ONT · Ontario | 557 | 80.3% | 61 min | 0.54% | B+ |
| DEN to DTW · Detroit | 486 | 79.6% | 83 min | 1.23% | B |
| DEN to SEA · Seattle | 439 | 82.7% | 54 min | 1.14% | B |
| DEN to SAT · San Antonio | 396 | 81.0% | 62 min | 0.25% | B+ |
| DEN to CVG · Cincinnati | 379 | 80.9% | 60 min | 0.79% | B+ |
| DEN to MIA · Miamithin sample | 353 | 73.9% | 63 min | 0.28% | C+ |
| DEN to ELP · El Pasothin sample | 348 | 80.1% | 66 min | 0.29% | B+ |
| DEN to OKC · Oklahoma Citythin sample | 338 | 81.2% | 69 min | 0.30% | B+ |
| DEN to ORD · Chicagothin sample | 321 | 64.1% | 83 min | 2.18% | D |
| DEN to BNA · Nashvillethin sample | 318 | 76.8% | 55 min | 0.63% | B+ |
| DEN to PHL · Philadelphiathin sample | 299 | 68.1% | 101 min | 3.68% | C− |
Flight by flight
Frontier Airlines flight numbers from DEN
29 Frontier Airlines flight numbers leaving DEN flew their main route often enough to have a record of their own. Grouped by destination.
- F9 3294to ATL 06:3087.5%
- F9 3600to ATL 09:5870.8%
- F9 2890to AUS 21:0063.6%
- F9 1402to BNA 07:5680.5%
- F9 1918to CLE 06:0087.4%
- F9 686to DCA 07:3592.6%
- F9 688to DCA 11:2576.0%
- F9 690to DCA 16:3865.7%
- F9 2996to IAH 21:0673.9%
- F9 3206to IAH 07:0086.2%
- F9 2348to IND 15:3580.7%
- F9 777to LAS 22:2972.1%
- F9 1993to LAS 10:0080.3%
- F9 2015to LAS 07:0088.4%
- F9 2349to LAS 16:2569.9%
- F9 2341to LAX 06:0089.8%
- F9 4345to LAX 22:3974.9%
- F9 2520to MCO 23:5965.8%
- F9 3312to MCO 09:2573.8%
- F9 1280to MIA 23:4075.3%
- F9 1292to MSP 21:0065.3%
- F9 1261to ONT 22:2976.9%
- F9 4753to PHX 22:3664.4%
- F9 2440to RDU 06:0387.4%
- F9 4989to SAN 22:2973.6%
- F9 3439to SFO 22:2970.3%
- F9 4251to SLC 22:2969.7%
- F9 3302to STL 06:0082.5%
- F9 2746to TPA 23:5974.3%
Departure window
Best time of day for this operation
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 21 points, against 17 points between the best and worst carrier.
- 5am–8am3,723 flights90.7%
- 8am–11am4,161 flights80.5%
- 11am–2pm3,115 flights83.1%
- 2pm–5pm4,040 flights76.6%
- 5pm–8pm2,431 flights69.4%
- 8pm–5am5,400 flights71.3%
Scale runs 60% to 95%.
Book the early departure. Flights leaving between 5am–8am arrive on time 90.7% of the time, against 69.4% for the evening window. That is 21 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 5,400 flights scheduled in it.
Across the year
Seasonal pattern
August is the worst month at 72.7% on time, 12 points below February, the best at 85.1%. 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. June was the busiest month here, with 2,150 flights.
Delay causes
What holds this operation up
- 41%Late-arriving aircraft
- 33%Carrier
- 23%National Airspace System
- 4%Extreme weather
41% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 332,000 reported delay minutes here, that single category outweighs weather by 11 to one. The split is drawn from 331,984 reported delay minutes.
Cancellations are rare at 0.77%, 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.
7.6% 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 a little over an hour, which a normal layover absorbs.
22,870 flights sit behind these numbers, which is a large enough sample that the headline rate is not moving on noise. Where a sub-group falls below 30 flights the site shows a dash instead of a percentage.
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 85.1% on time and August 72.7%, a swing of 12 points. If the dates move at all, move them out of August before you think about anything else. 22,662 completed flights over 12 months sit behind that.
Common questions
Frontier Airlines at DEN
How often is Frontier Airlines at DEN delayed?
About one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 21.5% of the 22,870 flights in this analysis, against 22.7% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on Frontier Airlines at DEN?
Delta Air Lines leads at 83.1% on time across 11,497 flights. JetBlue Airways is at the other end on 65.7%, a gap of 17 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on Frontier Airlines at DEN?
The 5am–8am departure window is the strongest at 90.7% on time. The 5pm–8pm window is the weakest at 69.4%, 21 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 Frontier Airlines at DEN?
August is the weakest month at 72.7% on time, compared with 85.1% in February. Across the year that is 12 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
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.