Carrier route record

F9IND→DEN

Frontier Airlines · Indianapolis to Denver

Flights: 294
Period: July 2025 to June 2026
Share of route: 12%
Carriers: 3

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

Frontier on IND to DEN lands a B+, level with the national rate of 77.6%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 294 flights. The strongest carrier on the route with a full sample, United Airlines, flew 841 at 80.6% on time.

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

On time

78.2%

Arrivals under 15 minutes late, of 293 completed flights

Avg delay

67 min

Across delayed arrivals only, not all flights

Cancelled

0.34%

National rate is 1.81%

Whole route

77.3%

Every carrier on IND to DEN, 2,540 flights

These figures cover 294 flights between July 2025 and June 2026. The median arrival is 11 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 IND to DEN

Frontier flew 294 of the 2,540 flights on IND to DEN, about 12% of it. Its 78.2% on time is about level with the route as a whole at 77.3%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from United at 80.6% to Southwest at 75.2%.

The two carriers here are closely matched: 5 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

On-time performance by carrier on IND to DEN
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	841	80.6%	68 min	0.83%	B+
Frontier Airlines (this page)thin sample	294	78.2%	67 min	0.34%	B+
Southwest Airlines	1,405	75.2%	50 min	0.50%	B+

No carrier stands out. United tops the table at 80.6%, 5 points clear of the bottom, which is inside the range this kind of sample moves year to year.

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 11 points, against 5 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am48 flights87.2%
8am–11am1 flights—
11am–2pm28 flights—
2pm–5pm8 flights—
5pm–8pm18 flights—
8pm–5am191 flights76.4%

Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 87.2% of the time, against 76.4% for the overnight window. That is 11 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 191 flights scheduled in it.

Across the year

Frontier on IND to DEN through the year

Jul–Sep 2025106 flights79.0%
Oct–Dec 202563 flights76.2%
Jan–Mar 202653 flights83.0%
Apr–Jun 202672 flights75.0%

Scale runs 65% to 90%. 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 78.2% on time across 294 flights.

Quarter by quarter Frontier on IND to DEN held fairly steady: 79.0% in Jul–Sep 2025, 76.2% in Oct–Dec 2025, 83.0% in Jan–Mar 2026 and 75.0% in Apr–Jun 2026. A spread of 8 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Across the week, Thursday is the strongest day at 83.9% on time and Friday the weakest at 72.7%. 11 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Frontier runs late on this route

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 4,268 reported delay minutes.

Late-arriving aircraft
42%
Carrier
34%
National Airspace System
22%
Extreme weather
2%

42% 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 4,268 reported delay minutes here, that single category outweighs weather by 20 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 4,268 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 87.2% on time here.

Cancellations are rare at 0.34%, below the national 1.81% 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.

Connections and stage length

What a delay here costs

7.8% 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 about an hour, which a normal layover absorbs.

The 976 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 81.6% on time across 294 flights, 3 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 3 points of difference.

One caution: this is a thin sample. 294 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 IND to DEN

Put together: treat all of this as provisional. 294 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 78.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 293 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