Carrier route record

F9ATL→SFO

Frontier Airlines · Atlanta to San Francisco

Flights: 310
Period: September 2025 to August 2026
Share of route: 9%
Carriers: 3

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

Frontier on ATL to SFO draws a C. About one flight in three arrives at least 15 minutes late, and the typical late arrival is about an hour behind schedule. Build slack into anything you connect to. That rests on 310 flights. The strongest carrier on the route with a full sample, United Airlines, flew 636 at 76.9% on time.

The national on-time rate over the same period is 77.3%, so Frontier on ATL to SFO runs 12 points behind the country as a whole. Across a thousand flights that is about 117 extra late arrivals.

On time

65.6%

Arrivals under 15 minutes late, of 305 completed flights

Avg delay

63 min

Across delayed arrivals only, not all flights

Cancelled

1.29%

National rate is 1.89%

Whole route

69.9%

Every carrier on ATL to SFO, 3,339 flights

These figures cover 310 flights between September 2025 and August 2026. Beyond the headline rate, 13.4% of arrivals land a full hour or more behind schedule, against 8.3% nationally.

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Carrier by carrier

Frontier against every carrier on ATL to SFO

Frontier flew 310 of the 3,339 flights on ATL to SFO, about 9% of it. Its 65.6% on time is 4 points worse than the route as a whole, which runs 69.9%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from United at 76.9% to Frontier at 65.6%.

The choice of carrier is not cosmetic here. United Airlines arrives on time 76.9% of the time; Delta Air Lines manages 68.5%. Sample sizes sit next to every figure, because a two-point gap across 2,393 flights means less than a ten-point one.

On-time performance by carrier on ATL to SFO
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	636	76.9%	69 min	0.47%	B+
Delta Air Lines	2,393	68.5%	55 min	0.67%	C+
Frontier Airlines (this page)thin sample	310	65.6%	63 min	1.29%	C

United leads Delta by 8 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

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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 19 points, against 8 points between the best and worst carrier.

5am–8am—
8am–11am39 flights73.7%
11am–2pm—
2pm–5pm86 flights77.4%
5pm–8pm185 flights58.5%
8pm–5am—

Scale runs 50% to 85%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 58.5% on time, against 77.4% for the 2pm–5pm slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5pm–8pm window is the busiest, with 185 flights scheduled in it.

Across the year

Frontier on ATL to SFO through the year

Jul–Sep 202521 flights—
Oct–Dec 202570 flights64.3%
Jan–Mar 202667 flights76.6%
Apr–Jun 202691 flights67.4%
Jul–Sep 202661 flights47.5%

Scale runs 40% to 80%. 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 65.6% on time across 310 flights.

Frontier on ATL to SFO did not run the same all year. Its best quarter was Jan–Mar 2026 at 76.6% on time and its weakest Jul–Sep 2026 at 47.5%, a swing of 29 points on roughly 78 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.

Across the week, Thursday is the strongest day at 77.6% on time and Sunday the weakest at 55.3%, a spread of 22 points.

Arrival by arrival

How late Frontier on ATL to SFO runs when it is late

Frontier on ATL to SFO often beats the schedule: 83 of 305 completed flights, 27%, arrived 15 minutes or more early. The 105 late arrivals split 27 under half an hour, 37 between 30 and 60 minutes, and 41 an hour or more.

15+ min early83 flights27.2%
Within 15 min117 flights38.4%
15–29 min late27 flights8.9%
30–59 min late37 flights12.1%
1–2 hours late28 flights9.2%
2+ hours late13 flights4.3%

Scale runs 0% to 100%.

Share of 305 completed flights by arrival against schedule.

A late pushback is often recovered here: of 155 departures that left 15 minutes late or more, 59 still arrived on time. 9 flights left on time and still arrived late.

The worst days

Worst days for Frontier on ATL to SFO

The latest arrival of the period was on 18 June 2026, 4 hours 8 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.

The latest arrivals of Frontier on ATL to SFO in the period
Date	Arrived late by	Largest filed cause
18 June 2026	4 hours 8 minutes	Carrier
7 December 2025	3 hours 33 minutes	Carrier
15 December 2025	3 hours 12 minutes	Carrier
5 January 2026	3 hours 3 minutes	National Airspace System
15 February 2026	3 hours	National Airspace System

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 6,577 reported delay minutes.

Late-arriving aircraft
39%
Carrier
32%
National Airspace System
28%
Extreme weather
2%

39% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 6,577 reported delay minutes here, that single category outweighs weather by 18 to one. The split is drawn from 6,577 reported delay minutes.

Cancellations sit at 1.29% against a national 1.89%, which is ordinary. Diversions add another 0.32%.

Connections and stage length

What a delay here costs

13.4% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.

At 2,139 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

The return leg is a different operation and performs like one: it runs 61.2% on time across 311 flights, 4 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 4 points of difference.

One caution: this is a thin sample. 310 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 ATL to SFO

Put together: treat all of this as provisional. 310 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 65.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 305 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures