Flight number record

F9 688

Frontier Airlines · Denver to Washington

Route: DEN → DCA
Departs: 11:38
Flights: 313
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s F9 688, check with Frontier Airlines.

F9 688 lands a B, level with the national rate of 77.6%. Roughly one flight in four 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 313 flights, with a median arrival 7 minutes early.

On time

77.3%

Arrivals under 15 minutes late, of 304 completed flights

Avg delay

76 min

Across delayed arrivals only, not all flights

Cancelled

1.28%

National rate is 1.81%

1 hour+ late

7.6%

National rate is 8.1%

These figures cover 313 flights between July 2025 and June 2026. The median arrival is 7 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.

Schedule

When F9 688 flies

F9 688 flies DEN to DCA without a single fixed slot. Its most common scheduled departure was 11:38, used on 67 of 313 flights, with 11:37 (65 flights) and 11:27 (52 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 11:3867 flights21.4%
Departs 11:3765 flights20.8%
Departs 11:2752 flights16.6%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.

A 11:38 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and F9 688 runs level with that at 77.3%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

F9 688 next to DEN to DCA

Every carrier on DEN to DCA combined arrived on time 81.2% of the time across 1,351 flights, so F9 688 is 4 points behind it. Frontier flew 986 flights on the same city pair under all its flight numbers, including this one, and those ran 78.4% on time. Across its whole network Frontier Airlines managed 73.2%, which this flight beats by 4 points.

F9 688 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
F9 688thin sample	313	77.3%	76 min	1.28%	B
All Frontier Airlines on DEN–DCA	986	78.4%	76 min	0.81%	B+
All carriers on DEN–DCA	1,351	81.2%	73 min	0.67%	B+
Frontier Airlines, whole network	205,332	73.2%	84 min	1.85%	C

Across the year

F9 688 quarter by quarter

Quarter by quarter F9 688 held fairly steady: 73.0% in Jul–Sep 2025, 79.3% in Oct–Dec 2025, 78.1% in Jan–Mar 2026 and 78.7% in Apr–Jun 2026. A spread of 6 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202579 flights73.0%
Oct–Dec 202582 flights79.3%
Jan–Mar 202676 flights78.1%
Apr–Jun 202676 flights78.7%

Scale runs 65% to 85%. Rows with fewer than 30 flights show a dash.

By weekday, F9 688 did best on Saturday at 91.7% on time and worst on Friday at 68.6%. Each day rests on about 45 flights, so a gap of 23 points is worth noticing but could still narrow in another year.

Delay causes

Why F9 688 runs late

One category carries most of the weight here. National Airspace System accounts for 45% of the 5,220 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.

National Airspace System
45%
Carrier
35%
Late-arriving aircraft
19%
Extreme weather
1%

The largest share of delay minutes, 35%, 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 1,819 of the 5,220 delay minutes reported here. The split is drawn from 5,220 delay minutes reported on F9 688.

Cancellations sit at 1.28% against a national 1.81%, which is ordinary. Diversions add another 1.60%.

Connections and routes

What a delay on this flight costs

7.6% 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 same number turns up on one other city pair in the data, including RDU to DCA (1), but none flew often enough under F9 688 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DEN to DCA only.

One caution: this is a thin sample. 313 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 F9 688

For a booking, read F9 688 as 77.3% on time with 1.28% cancelled over 313 flights. Those are rates from the past twelve months, not a forecast for any particular day.

Where to go next

A flight number here means Frontier Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.

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