Carrier route record

F9SFO→ATL

Frontier Airlines · San Francisco to Atlanta

Flights: 306
Period: July 2025 to June 2026
Share of route: 9%
Carriers: 3

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

Frontier on SFO to ATL draws a D−. Roughly one flight in two arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 306 flights. The strongest carrier on the route with a full sample, United Airlines, flew 637 at 86.5% on time.

The national on-time rate over the same period is 77.6%, so Frontier on SFO to ATL runs 18 points behind the country as a whole. Across a thousand flights that is about 179 extra late arrivals.

On time

59.7%

Arrivals under 15 minutes late, of 295 completed flights

Avg delay

72 min

Across delayed arrivals only, not all flights

Cancelled

3.27%

National rate is 1.81%

Whole route

81.6%

Every carrier on SFO to ATL, 3,350 flights

These figures cover 306 flights between July 2025 and June 2026. Beyond the headline rate, 14.9% 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.

Carrier by carrier

Frontier against every carrier on SFO to ATL

Frontier flew 306 of the 3,350 flights on SFO to ATL, about 9% of it. Its 59.7% on time is 22 points worse than the route as a whole, which runs 81.6%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from United at 86.5% to Frontier at 59.7%.

The two carriers here are closely matched: 4 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

On-time performance by carrier on SFO to ATL
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	637	86.5%	54 min	0.16%	A+
Delta Air Lines	2,407	83.0%	68 min	0.66%	B+
Frontier Airlines (this page)thin sample	306	59.7%	72 min	3.27%	D−

No carrier stands out. United tops the table at 86.5%, 4 points clear of the bottom, which is inside the range this kind of sample moves year to year.

Flight by flight

Frontier flight numbers on SFO to ATL

F9 144822:2959.7% · 306 flights

Departure window

When Frontier runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 306 flights.

The overnight block holds up unusually well at 59.7% on time across 306 flights. Red-eyes fly into empty airspace and empty gates, and they are the first rotation of the aircraft's day rather than the last. The 8pm–5am window is the busiest, with 306 flights scheduled in it.

Across the year

Frontier on SFO to ATL through the year

Jul–Sep 202578 flights50.6%
Oct–Dec 202570 flights66.2%
Jan–Mar 202667 flights71.0%
Apr–Jun 202691 flights54.5%

Scale runs 40% to 75%. 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 59.7% on time across 306 flights.

Frontier on SFO to ATL did not run the same all year. Its best quarter was Jan–Mar 2026 at 71.0% on time and its weakest Jul–Sep 2025 at 50.6%, a swing of 20 points on roughly 77 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, Saturday is the strongest day at 68.8% on time and Friday the weakest at 44.7%. 24 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Frontier runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 61% of the 8,601 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
61%
Carrier
28%
National Airspace System
8%
Extreme weather
2%

61% 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 8,601 reported delay minutes here, that single category outweighs weather by 35 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 8,601 reported delay minutes.

Cancellations run at 3.27%, against 1.81% nationally. That is about one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and stage length

What a delay here costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 14.9% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum 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 66.6% on time across 307 flights, 7 points above 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 7 points of difference.

One caution: this is a thin sample. 306 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 SFO to ATL

Put together: the delay figures matter less here than the 3.27% cancellation rate. A late arrival costs you a little over an hour; a cancelled flight costs you the day. Book the 8pm–5am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 295 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