Carrier route record

OOSEA→SMF

SkyWest Airlines · Seattle to Sacramento

Flights: 1,941
Period: July 2025 to June 2026
Share of route: 44%
Carriers: 3

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

SkyWest on SEA to SMF earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 12 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 1,941 flights. The strongest carrier on the route with a full sample, Alaska Airlines, flew 1,310 at 79.8% on time.

Set against the rest of the country, SkyWest's SEA to SMF record is 12 points better than the US average of 77.6%. That gap is worth roughly 117 fewer late arrivals for every thousand flights.

On time

89.3%

Arrivals under 15 minutes late, of 1,931 completed flights

Avg delay

62 min

Across delayed arrivals only, not all flights

Cancelled

0.26%

National rate is 1.81%

Whole route

81.9%

Every carrier on SEA to SMF, 4,407 flights

These figures cover 1,941 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.

Carrier by carrier

SkyWest against every carrier on SEA to SMF

SkyWest flew 1,941 of the 4,407 flights on SEA to SMF, about 44% of it. Its 89.3% on time is 7 points better than the route as a whole, which runs 81.9%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from SkyWest at 89.3% to Southwest at 71.9%.

The choice of carrier is not cosmetic here. Alaska Airlines arrives on time 79.8% of the time; Southwest Airlines manages 71.9%. Sample sizes sit next to every figure, because a two-point gap across 1,156 flights means less than a ten-point one.

On-time performance by carrier on SEA to SMF
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines (this page)	1,941	89.3%	62 min	0.26%	A+
Alaska Airlines	1,310	79.8%	44 min	0.61%	B+
Southwest Airlines	1,156	71.9%	48 min	0.43%	C+

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

Flight by flight

SkyWest flight numbers on SEA to SMF

Departure window

When SkyWest runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 10 points, against 8 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am70 flights81.4%
8am–11am780 flights91.7%
11am–2pm64 flights89.1%
2pm–5pm585 flights86.9%
5pm–8pm172 flights86.0%
8pm–5am270 flights91.4%

Scale runs 75% to 95%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 91.7% of the time, against 81.4% for the early window. That is 10 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 780 flights scheduled in it.

Across the year

SkyWest on SEA to SMF through the year

Darker means more delays. Figures are on-time percentages.May best, December worst

December is the weak month at 81.6% on time, against 93.3% in May. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. July was the busiest month here, with 208 flights.

Across the week, Tuesday is the strongest day at 93.0% on time and Thursday the weakest at 86.2%. 7 points is a smaller lever than departure hour, but it is free.

Delay causes

Why SkyWest runs late on this route

One category carries most of the weight here. Carrier accounts for 57% of the 13,000 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.

Carrier
57%
Extreme weather
22%
Late-arriving aircraft
13%
National Airspace System
8%
Security
0%

Extreme weather accounts for 22% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 3.5 times the usual weather exposure. The split is drawn from 12,722 reported delay minutes.

The largest share of delay minutes, 57%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 7,311 of the 13,000 delay minutes reported here.

Cancellations are rare at 0.26%, 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 stage length

What a delay here costs

Badly late arrivals are rare here: only 3.6% 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 605 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.

The return leg runs 87.4% on time across 1,952 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 1,941 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.

What to do with this

Booking SkyWest on SEA to SMF

Put together: take the 8am–11am departure, avoid December if the dates are flexible, and if two carriers are within a few dollars of each other, Alaska is the one with the record behind it. None of that guarantees an on-time arrival; it moves the odds by 10 points, which is the most any booking decision can do. 1,931 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