Carrier route record

F9DEN→GEG

Frontier Airlines · Denver to Spokane

Flights: 122
Period: July 2025 to June 2026
Share of route: 6%
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 GEG earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs about 35 minutes. That rests on 122 flights. The strongest carrier on the route with a full sample, United Airlines, flew 833 at 74.3% on time.

Set against the rest of the country, Frontier's DEN to GEG record is 9 points better than the US average of 77.6%. That gap is worth roughly 85 fewer late arrivals for every thousand flights.

On time

86.1%

Arrivals under 15 minutes late, of 122 completed flights

Avg delay

34 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.81%

Whole route

75.2%

Every carrier on DEN to GEG, 2,062 flights

These figures cover 122 flights between July 2025 and June 2026. The median arrival is 5 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 GEG

Frontier flew 122 of the 2,062 flights on DEN to GEG, about 6% of it. Its 86.1% on time is 11 points better than the route as a whole, which runs 75.2%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from SkyWest at 90.3% to Southwest at 70.1%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The two carriers here are closely matched: 4 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 DEN to GEG
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlinesthin sample	250	90.3%	47 min	0.80%	A+
Frontier Airlines (this page)thin sample	122	86.1%	34 min	0.00%	A+
United Airlines	833	74.3%	53 min	0.24%	C+
Southwest Airlines	857	70.1%	48 min	0.35%	C+

No carrier stands out. United tops the table at 74.3%, 4 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 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 122 flights.

There are not enough flights in each departure window to split Frontier's DEN to GEG record by time of day without the percentages moving on noise. The headline rate of 86.1% is the reliable figure here.

Across the year

Frontier on DEN to GEG through the year

Jul–Sep 202537 flights81.1%
Oct–Dec 202530 flights86.7%
Jan–Mar 202626 flights—
Apr–Jun 202629 flights—

Scale runs 75% 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 86.1% on time across 122 flights.

Split by quarter, Frontier on DEN to GEG logged 37 flights in Jul–Sep 2025, 30 flights in Oct–Dec 2025, 26 flights in Jan–Mar 2026 and 29 flights in Apr–Jun 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 86.1% annual figure is the one to use.

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 585 reported delay minutes.

Carrier
37%
Late-arriving aircraft
32%
National Airspace System
31%

The largest share of delay minutes, 37%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 215 of the 585 delay minutes reported here. The split is drawn from 585 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 85.6% on time here.

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

Badly late arrivals are rare here: only 1.6% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

The 836 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 77.7% on time across 122 flights, 8 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 8 points of difference.

One caution: this is a thin sample. 122 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 GEG

Put together: treat all of this as provisional. 122 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 86.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 122 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