Carrier route record

F9DEN→GRR

Frontier Airlines · Denver to Grand Rapids

Flights: 147
Period: July 2025 to June 2026
Share of route: 12%
Carriers: 4

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

Frontier on DEN to GRR earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 10 points better than the national rate of 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 147 flights, with a median arrival 10 minutes early.

Set against the rest of the country, Frontier's DEN to GRR record is 10 points better than the US average of 77.6%. That gap is worth roughly 95 fewer late arrivals for every thousand flights.

On time

87.1%

Arrivals under 15 minutes late, of 147 completed flights

Avg delay

74 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.81%

Whole route

75.3%

Every carrier on DEN to GRR, 1,239 flights

These figures cover 147 flights between July 2025 and June 2026. The median arrival is 10 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 GRR

Frontier flew 147 of the 1,239 flights on DEN to GRR, about 12% of it. Its 87.1% on time is 12 points better than the route as a whole, which runs 75.3%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from SkyWest at 100.0% to Southwest at 67.6%. Two 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 DEN to GRR
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlinesthin sample	1	100.0%	—	0.00%	A+
Frontier Airlines (this page)thin sample	147	87.1%	74 min	0.00%	A+
United Airlines	728	76.7%	54 min	0.27%	B+
Southwest Airlinesthin sample	363	67.6%	45 min	0.28%	C+

Departure window

When Frontier runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 147 flights.

There are not enough flights in each departure window to split Frontier's DEN to GRR record by time of day without the percentages moving on noise. The headline rate of 87.1% is the reliable figure here.

Across the year

Frontier on DEN to GRR through the year

Jul–Sep 202565 flights89.2%
Oct–Dec 202536 flights80.6%
Jan–Mar 20263 flights—
Apr–Jun 202643 flights88.4%

Scale runs 70% to 95%. 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 87.1% on time across 147 flights.

Quarter by quarter Frontier on DEN to GRR held fairly steady: 89.2% in Jul–Sep 2025, 80.6% in Oct–Dec 2025 and 88.4% in Apr–Jun 2026. A spread of 9 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 94.3% on time and Monday the weakest at 88.6%. 6 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 54% of the 1,397 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
54%
Carrier
27%
National Airspace System
15%
Extreme weather
5%

54% 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 1,397 reported delay minutes here, that single category outweighs weather by 12 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 1,397 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

5.4% 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.

The 1,015 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 74.5% on time across 146 flights, 13 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 13 points of difference.

One caution: this is a thin sample. 147 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 GRR

Put together: treat all of this as provisional. 147 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 87.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 147 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