Carrier route record

F9DEN→FSD

Frontier Airlines · Denver to Sioux Falls

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 DEN to FSD sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 158 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 1,307 at 84.7% on time.

The US average over the same twelve months is 77.6%, so there is little to separate Frontier on DEN to FSD from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

75.3%

Arrivals under 15 minutes late, of 158 completed flights

Avg delay

72 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.81%

Whole route

81.6%

Every carrier on DEN to FSD, 1,831 flights

These figures cover 158 flights between July 2025 and June 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.

Carrier by carrier

Frontier against every carrier on DEN to FSD

Frontier flew 158 of the 1,831 flights on DEN to FSD, about 9% of it. Its 75.3% on time is 6 points worse than the route as a whole, which runs 81.6%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from SkyWest at 84.7% to United at 73.1%.

The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 84.7% of the time; United Airlines manages 73.1%. 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 DEN to FSD
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines	1,307	84.7%	79 min	1.07%	B
Frontier Airlines (this page)thin sample	158	75.3%	72 min	0.00%	B+
United Airlines	366	73.1%	103 min	0.82%	C+

SkyWest leads United by 12 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

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 27 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–11am20 flights—
11am–2pm66 flights86.4%
2pm–5pm52 flights59.6%
5pm–8pm20 flights—
8pm–5am—

Scale runs 50% to 90%. Rows with fewer than 30 flights show a dash.

The best window here is not the first bank but the 11am–2pm slot at 86.4% on time, ahead of 2pm–5pm at 59.6%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 11am–2pm window is the busiest, with 66 flights scheduled in it.

Across the year

Frontier on DEN to FSD through the year

Jul–Sep 202557 flights71.9%
Oct–Dec 202540 flights70.0%
Jan–Mar 202627 flights—
Apr–Jun 202634 flights76.5%

Scale runs 60% to 80%. 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 75.3% on time across 158 flights.

Quarter by quarter Frontier on DEN to FSD held fairly steady: 71.9% in Jul–Sep 2025, 70.0% in Oct–Dec 2025 and 76.5% in Apr–Jun 2026. A spread of 7 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Across the week, Friday is the strongest day at 82.2% on time and Monday the weakest at 60.0%. 22 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 69% of the 2,791 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
69%
Carrier
16%
National Airspace System
12%
Extreme weather
2%

69% 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 2,791 reported delay minutes here, that single category outweighs weather by 33 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 2,791 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

6.3% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says 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.

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 11am–2pm window matters as much as it does.

The return leg is a different operation and performs like one: it runs 70.3% on time across 158 flights, 5 points below 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 DEN to FSD

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 75.3% 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