Carrier route record

F9DCA→DEN

Frontier Airlines · Washington to Denver

Flights: 984
Period: July 2025 to June 2026
Share of route: 73%
Carriers: 2

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

Frontier on DCA to DEN lands a B+, about a point better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 984 flights, with a median arrival 8 minutes early.

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

On time

78.4%

Arrivals under 15 minutes late, of 974 completed flights

Avg delay

80 min

Across delayed arrivals only, not all flights

Cancelled

0.91%

National rate is 1.81%

Whole route

78.5%

Every carrier on DCA to DEN, 1,349 flights

These figures cover 984 flights between July 2025 and June 2026. The median arrival is 8 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 DCA to DEN

Frontier flew 984 of the 1,349 flights on DCA to DEN, most of the route. Its 78.4% on time is about level with the route as a whole at 78.5%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from United at 78.8% to Frontier at 78.4%.

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 DCA to DEN
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	365	78.8%	104 min	0.27%	B+
Frontier Airlines (this page)	984	78.4%	80 min	0.91%	B+

Flight by flight

Frontier flight numbers on DCA to DEN

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 28 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–8am190 flights84.1%
8am–11am169 flights85.6%
11am–2pm119 flights93.2%
2pm–5pm201 flights78.4%
5pm–8pm305 flights65.1%
8pm–5am—

Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.

The best window here is not the first bank but the 11am–2pm slot at 93.2% on time, ahead of 5pm–8pm at 65.1%. 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 5pm–8pm window is the busiest, with 305 flights scheduled in it.

Across the year

Frontier on DCA to DEN through the year

Darker means more delays. Figures are on-time percentages.October best, July worst

July is the worst month at 70.4% on time, 19 points below October, the best at 89.2%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. January was the busiest month here, with 85 flights.

Across the week, Saturday is the strongest day at 87.5% on time and Thursday the weakest at 73.5%. 14 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 17,000 reported delay minutes.

National Airspace System
36%
Late-arriving aircraft
27%
Carrier
22%
Extreme weather
15%

Extreme weather accounts for 15% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.3 times the usual weather exposure. The split is drawn from 16,791 reported delay minutes.

36% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 6,060 minutes out of 17,000, against a national NAS share of 21%.

Cancellations sit at 0.91% against a national 1.81%, which is ordinary. Diversions add another 0.10%.

Connections and stage length

What a delay here costs

7.9% 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 1,476 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 runs 78.4% on time across 986 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 984 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 DCA to DEN

Put together: treat all of this as provisional. 984 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 78.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 974 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