Carrier route record

UALAX→SMF

United Airlines · Los Angeles to Sacramento

Flights: 201
Period: July 2025 to June 2026
Share of route: 4%
Carriers: 5

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

United on LAX to SMF lands a B+, 6 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by roughly 40 minutes on average. That is a workable record, not a spotless one. That rests on 201 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 3,517 at 87.8% on time.

Set against the rest of the country, United's LAX to SMF record is 6 points better than the US average of 77.6%. That gap is worth roughly 59 fewer late arrivals for every thousand flights.

On time

83.5%

Arrivals under 15 minutes late, of 200 completed flights

Avg delay

42 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.81%

Whole route

84.6%

Every carrier on LAX to SMF, 5,634 flights

These figures cover 201 flights between July 2025 and June 2026. The median arrival is 8 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.

Carrier by carrier

United against every carrier on LAX to SMF

United flew 201 of the 5,634 flights on LAX to SMF, about 4% of it. Its 83.5% on time is about level with the route as a whole at 84.6%. Ranked by on-time rate it is number three of five carriers on the route, where the range runs from SkyWest at 87.8% to Delta at 67.0%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 87.8% of the time; Southwest Airlines manages 79.0%. Sample sizes sit next to every figure, because a two-point gap across 1,614 flights means less than a ten-point one.

On-time performance by carrier on LAX to SMF
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines	3,517	87.8%	74 min	0.43%	A+
Frontier Airlinesthin sample	204	83.5%	56 min	1.96%	B
United Airlines (this page)thin sample	201	83.5%	42 min	0.00%	B+
Southwest Airlines	1,614	79.0%	53 min	0.19%	B+
Delta Air Linesthin sample	98	67.0%	66 min	1.02%	C

SkyWest leads Southwest by 9 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Departure window

When United 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 201 flights.

5am–8am—
8am–11am105 flights86.5%
11am–2pm—
2pm–5pm—
5pm–8pm88 flights80.7%
8pm–5am8 flights—

Scale runs 70% to 90%. Rows with fewer than 30 flights show a dash.

The early departures do better, though not dramatically: 86.5% on time for the 8am–11am window against 80.7% for 5pm–8pm. Worth taking if the schedule allows, not worth an extra connection. The 8am–11am window is the busiest, with 105 flights scheduled in it.

Across the year

United on LAX to SMF through the year

Oct–Dec 202518 flights—
Jan–Mar 2026104 flights81.6%
Apr–Jun 202679 flights83.5%

Scale runs 75% to 90%. 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 83.5% on time across 201 flights.

Split by quarter, United on LAX to SMF logged 18 flights in Oct–Dec 2025, 104 flights in Jan–Mar 2026 and 79 flights in Apr–Jun 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 83.5% annual figure is the one to use.

Across the week, Friday is the strongest day at 88.9% on time and Sunday the weakest at 73.5%. 15 points is a smaller lever than departure hour, but it is free.

Delay causes

Why United runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 53% of the 1,375 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
53%
Carrier
33%
National Airspace System
14%

53% 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 1,375 reported delay minutes here, that single category outweighs weather by 53 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 1,375 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 86.5% on time here.

Cancellations are rare at 0.00%, below the national 1.81% and low enough to earn the plus on the grade. Almost no flights are called off; the risk here is arriving late, not not arriving.

Connections and stage length

What a delay here costs

Badly late arrivals are rare here: only 3.5% 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.

At 373 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 8am–11am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 91.5% on time across 201 flights, 8 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 8 points of difference.

One caution: this is a thin sample. 201 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 United on LAX to SMF

Put together: treat all of this as provisional. 201 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 83.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 200 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