Flight number record

F9 2231

Frontier Airlines · Las Vegas to Ontario

Route: LAS → ONT
Departs: 19:45
Flights: 290
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s F9 2231, check with Frontier Airlines.

F9 2231 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 a little over an hour on average. That is a workable record, not a spotless one. That rests on 290 flights, with a median arrival 13 minutes early.

On time

78.0%

Arrivals under 15 minutes late, of 286 completed flights

Avg delay

73 min

Across delayed arrivals only, not all flights

Cancelled

1.38%

National rate is 1.81%

1 hour+ late

8.4%

National rate is 8.1%

These figures cover 290 flights between July 2025 and June 2026. Beyond the headline rate, 8.4% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Schedule

When F9 2231 flies

F9 2231 flies LAS to ONT without a single fixed slot. Its most common scheduled departure was 19:45, used on 46 of 290 flights, with 20:13 (29 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 19:4546 flights15.9%
Departs 20:1329 flights10.0%

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 19:45 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and F9 2231 runs 10 points better at 78.0%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

Against the route

F9 2231 next to LAS to ONT

Every carrier on LAS to ONT combined arrived on time 75.8% of the time across 2,479 flights, so F9 2231 is 2 points ahead of it. Frontier flew 724 flights on the same city pair under all its flight numbers, including this one, and those ran 82.0% on time. Across its whole network Frontier Airlines managed 73.2%, which this flight beats by 5 points.

F9 2231 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
F9 2231thin sample	290	78.0%	73 min	1.38%	B
All Frontier Airlines on LAS–ONT	724	82.0%	77 min	0.83%	B+
All carriers on LAS–ONT	2,479	75.8%	55 min	0.77%	B+
Frontier Airlines, whole network	205,332	73.2%	84 min	1.85%	C

Across the year

F9 2231 quarter by quarter

Quarter by quarter F9 2231 held fairly steady: 78.3% in Jul–Sep 2025, 76.9% in Oct–Dec 2025, 80.0% in Jan–Mar 2026 and 77.6% in Apr–Jun 2026. A spread of 3 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202584 flights78.3%
Oct–Dec 202592 flights76.9%
Jan–Mar 202647 flights80.0%
Apr–Jun 202667 flights77.6%

Scale runs 70% to 85%. Rows with fewer than 30 flights show a dash.

By weekday, F9 2231 did best on Tuesday at 88.6% on time and worst on Friday at 61.9%. Each day rests on about 41 flights, so a gap of 27 points is worth noticing but could still narrow in another year.

Delay causes

Why F9 2231 runs late

One category carries most of the weight here. Late-arriving aircraft accounts for 72% of the 4,616 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
72%
Carrier
22%
National Airspace System
6%
Extreme weather
0%

72% 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 4,616 reported delay minutes here, that single category outweighs weather by 72 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 4,616 delay minutes reported on F9 2231.

Cancellations sit at 1.38% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and routes

What a delay on this flight costs

8.4% 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.

Every one of the 290 flights under F9 2231 in the data flew LAS to ONT. 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. 290 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 2231

For a booking, read F9 2231 as 78.0% on time with 1.38% cancelled over 290 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