Carrier route record

F9FSD→DEN

Frontier Airlines · Sioux Falls to Denver

Flights: 158
Period: July 2025 to June 2026
Share of route: 9%
Carriers: 3

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.

Frontier on FSD to DEN sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 158 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 1,308 at 81.9% on time.

The national on-time rate over the same period is 77.6%, so Frontier on FSD to DEN runs 7 points behind the country as a whole. Across a thousand flights that is about 73 extra late arrivals.

On time

70.3%

Arrivals under 15 minutes late, of 158 completed flights

Avg delay

97 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.81%

Whole route

78.4%

Every carrier on FSD to DEN, 1,832 flights

These figures cover 158 flights between July 2025 and June 2026. Beyond the headline rate, 13.3% 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.

Carrier by carrier

Frontier against every carrier on FSD to DEN

Frontier flew 158 of the 1,832 flights on FSD to DEN, about 9% of it. Its 70.3% on time is 8 points worse than the route as a whole, which runs 78.4%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from SkyWest at 81.9% to United at 69.7%.

The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 81.9% of the time; United Airlines manages 69.7%. Sample sizes sit next to every figure, because a two-point gap across 366 flights means less than a ten-point one.

On-time performance by carrier on FSD to DEN
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines	1,308	81.9%	105 min	1.45%	B
Frontier Airlines (this page)thin sample	158	70.3%	97 min	0.00%	C+
United Airlines	366	69.7%	62 min	1.64%	C

The spread between SkyWest and United is 12 points, wide enough that it should decide the booking. On a hundred trips that is 12 more arrivals inside the on-time window.

Departure window

When Frontier runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 26 points, against 12 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am—
8am–11am—
11am–2pm2 flights—
2pm–5pm84 flights77.4%
5pm–8pm37 flights51.4%
8pm–5am35 flights71.4%

Scale runs 45% to 85%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 51.4% on time, against 77.4% for the 2pm–5pm 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 2pm–5pm window is the busiest, with 84 flights scheduled in it.

Across the year

Frontier on FSD to DEN through the year

Jul–Sep 202557 flights63.2%
Oct–Dec 202540 flights77.5%
Jan–Mar 202627 flights—
Apr–Jun 202634 flights58.8%

Scale runs 50% to 85%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 70.3% on time across 158 flights.

Frontier on FSD to DEN did not run the same all year. Its best quarter was Oct–Dec 2025 at 77.5% on time and its weakest Apr–Jun 2026 at 58.8%, a swing of 19 points on roughly 53 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.

Across the week, Friday is the strongest day at 73.3% on time and Monday the weakest at 62.2%. 11 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Frontier runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 52% of the 4,566 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.

Late-arriving aircraft
52%
National Airspace System
28%
Carrier
17%
Extreme weather
3%

52% 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 4,566 reported delay minutes here, that single category outweighs weather by 19 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 4,566 reported delay minutes.

Cancellations are rare at 0.00%, below the national 1.81% and low enough to earn the plus on the grade. Almost no flights are called off; the risk here is arriving late, not not arriving.

Connections and stage length

What a delay here costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 13.3% 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.

At 483 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 2pm–5pm window matters as much as it does.

The return leg is a different operation and performs like one: it runs 75.3% on time across 158 flights, 5 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 5 points of difference.

One caution: this is a thin sample. 158 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 Frontier on FSD to DEN

Put together: treat all of this as provisional. 158 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 70.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 158 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures