Flight number record

F9 4371

Frontier Airlines · Denver to Santa Ana

Route: DEN → SNA
Departs: 09:43
Flights: 292
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s F9 4371, check with Frontier Airlines.

F9 4371 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 an hour. That rests on 292 flights, with a median arrival 9 minutes early.

Set against the rest of the country, F9 4371's record is 9 points better than the US average of 77.6%. That gap is worth roughly 93 fewer late arrivals for every thousand flights.

On time

86.9%

Arrivals under 15 minutes late, of 291 completed flights

Avg delay

58 min

Across delayed arrivals only, not all flights

Cancelled

0.34%

National rate is 1.81%

1 hour+ late

4.5%

National rate is 8.1%

These figures cover 292 flights between July 2025 and June 2026. The median arrival is 9 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 4371 flies

F9 4371 flies DEN to SNA without a single fixed slot. Its most common scheduled departure was 09:43, used on 31 of 292 flights. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 09:4331 flights10.6%

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 09:43 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and F9 4371 runs 3 points better at 86.9%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Against the route

F9 4371 next to DEN to SNA

Every carrier on DEN to SNA combined arrived on time 80.1% of the time across 3,696 flights, so F9 4371 is 7 points ahead of it. Across its whole network Frontier Airlines managed 73.2%, which this flight beats by 14 points.

F9 4371 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
F9 4371thin sample	292	86.9%	58 min	0.34%	A+
All Frontier Airlines on DEN–SNAthin sample	292	86.9%	58 min	0.34%	A+
All carriers on DEN–SNA	3,696	80.1%	47 min	0.35%	B+
Frontier Airlines, whole network	205,332	73.2%	84 min	1.85%	C

Across the year

F9 4371 quarter by quarter

F9 4371 did not run the same all year. Its best quarter was Apr–Jun 2026 at 96.7% on time and its weakest Jul–Sep 2025 at 79.1%, a swing of 18 points on roughly 73 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.

Jul–Sep 202586 flights79.1%
Oct–Dec 202586 flights85.9%
Jan–Mar 202660 flights90.0%
Apr–Jun 202660 flights96.7%

Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, F9 4371 ranged from 84.0% on Monday to 90.4% on Sunday. With about 42 flights behind each day, a spread of 6 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why F9 4371 runs late

One category carries most of the weight here. Late-arriving aircraft accounts for 45% of the 2,217 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
45%
Carrier
39%
National Airspace System
15%
Extreme weather
1%

45% 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 2,217 reported delay minutes here, that single category outweighs weather by 32 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 2,217 delay minutes reported on F9 4371.

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 routes

What a delay on this flight costs

Badly late arrivals are rare here: only 4.5% 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 846 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.

Every one of the 292 flights under F9 4371 in the data flew DEN to SNA. The number was not reused on any other city pair, which makes this a clean record of one route.

One caution: this is a thin sample. 292 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 4371

For a booking, F9 4371 has one of the better records a US domestic flight can show: 86.9% on time and 0.34% cancelled. That is a base rate, not a promise about any single 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