Carrier route record

F9MSN→DEN

Frontier Airlines · Madison to Denver

Flights: 141
Period: July 2025 to June 2026
Share of route: 13%
Carriers: 3

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

Frontier on MSN to DEN draws a C. About one flight in three arrives at least 15 minutes late, and the typical late arrival is close to two hours behind schedule. Build slack into anything you connect to. That rests on 141 flights, with a median arrival 3 minutes early.

The national on-time rate over the same period is 77.6%, so Frontier on MSN to DEN runs 10 points behind the country as a whole. Across a thousand flights that is about 102 extra late arrivals.

On time

67.4%

Arrivals under 15 minutes late, of 138 completed flights

Avg delay

117 min

Across delayed arrivals only, not all flights

Cancelled

1.42%

National rate is 1.81%

Whole route

80.1%

Every carrier on MSN to DEN, 1,074 flights

These figures cover 141 flights between July 2025 and June 2026. Beyond the headline rate, 17.4% 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 MSN to DEN

Frontier flew 141 of the 1,074 flights on MSN to DEN, about 13% of it. Its 67.4% on time is 13 points worse than the route as a whole, which runs 80.1%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from United at 84.2% to Frontier at 67.4%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on MSN to DEN
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	730	84.2%	69 min	0.68%	B+
SkyWest Airlinesthin sample	203	74.1%	87 min	0.49%	C+
Frontier Airlines (this page)thin sample	141	67.4%	117 min	1.42%	C

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 16 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am—
8am–11am1 flights—
11am–2pm2 flights—
2pm–5pm21 flights—
5pm–8pm32 flights56.2%
8pm–5am85 flights71.8%

Scale runs 50% to 75%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 56.2% on time, against 71.8% for the 8pm–5am 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 8pm–5am window is the busiest, with 85 flights scheduled in it.

Across the year

Frontier on MSN to DEN through the year

Jul–Sep 202544 flights59.1%
Oct–Dec 202548 flights68.1%
Jan–Mar 202618 flights—
Apr–Jun 202631 flights76.7%

Scale runs 50% 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 67.4% on time across 141 flights.

Frontier on MSN to DEN did not run the same all year. Its best quarter was Apr–Jun 2026 at 76.7% on time and its weakest Jul–Sep 2025 at 59.1%, a swing of 18 points on roughly 47 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, Sunday is the strongest day at 73.2% on time and Thursday the weakest at 66.7%. 7 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 70% of the 5,282 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
70%
National Airspace System
16%
Carrier
13%
Extreme weather
1%

70% 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 5,282 reported delay minutes here, that single category outweighs weather by 53 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 5,282 reported delay minutes.

Cancellations sit at 1.42% against a national 1.81%, which is ordinary. Diversions add another 0.71%.

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. 17.4% 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 826 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.

The return leg is a different operation and performs like one: it runs 78.0% on time across 142 flights, 11 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 11 points of difference.

One caution: this is a thin sample. 141 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 MSN to DEN

Put together: treat all of this as provisional. 141 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 67.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 138 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