Flight number record

OO 4131

SkyWest Airlines · Seattle to Sacramento

Route: SEA → SMF
Departs: 19:45
Flights: 319
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s OO 4131, check with SkyWest Airlines. SkyWest Airlines flies under contract for larger airlines, so a ticket for this flight may show a different airline code and number.

OO 4131 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 14 points better than the national rate of 77.6%. When something does go wrong the average delay runs roughly 55 minutes. That rests on 319 flights, with a median arrival 13 minutes early.

Set against the rest of the country, OO 4131's record is 14 points better than the US average of 77.6%. That gap is worth roughly 136 fewer late arrivals for every thousand flights.

On time

91.2%

Arrivals under 15 minutes late, of 318 completed flights

Avg delay

53 min

Across delayed arrivals only, not all flights

Cancelled

0.31%

National rate is 1.81%

1 hour+ late

2.2%

National rate is 8.1%

These figures cover 319 flights between July 2025 and June 2026. The median arrival is 13 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.

Schedule

When OO 4131 flies

OO 4131 flies SEA to SMF without a single fixed slot. Its most common scheduled departure was 19:45, used on 62 of 319 flights, with 19:50 (57 flights) and 19:59 (41 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 19:4562 flights19.4%
Departs 19:5057 flights17.9%
Departs 19:5941 flights12.9%

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 OO 4131 runs 23 points better at 91.2%. 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

OO 4131 next to SEA to SMF

Every carrier on SEA to SMF combined arrived on time 81.9% of the time across 4,407 flights, so OO 4131 is 9 points ahead of it. SkyWest flew 1,941 flights on the same city pair under all its flight numbers, including this one, and those ran 89.3% on time. Across its whole network SkyWest Airlines managed 79.0%, which this flight beats by 12 points.

OO 4131 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 4131thin sample	319	91.2%	53 min	0.31%	A+
All SkyWest Airlines on SEA–SMF	1,941	89.3%	62 min	0.26%	A+
All carriers on SEA–SMF	4,407	81.9%	50 min	0.41%	B+
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	B

Across the year

OO 4131 quarter by quarter

Quarter by quarter OO 4131 held fairly steady: 91.4% in Jul–Sep 2025, 88.3% in Oct–Dec 2025, 95.0% in Jan–Mar 2026 and 90.1% in Apr–Jun 2026. A spread of 7 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202570 flights91.4%
Oct–Dec 202577 flights88.3%
Jan–Mar 202681 flights95.0%
Apr–Jun 202691 flights90.1%

Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, OO 4131 did best on Wednesday at 97.9% on time and worst on Thursday at 80.9%. Each day rests on about 46 flights, so a gap of 17 points is worth noticing but could still narrow in another year.

Delay causes

Why OO 4131 runs late

One category carries most of the weight here. Carrier accounts for 88% of the 1,474 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
88%
Extreme weather
7%
National Airspace System
3%
Security
2%

The largest share of delay minutes, 88%, 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 1,304 of the 1,474 delay minutes reported here. The split is drawn from 1,474 delay minutes reported on OO 4131.

Cancellations are rare at 0.31%, 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 routes

What a delay on this flight costs

Badly late arrivals are rare here: only 2.2% 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 same number turns up on one other city pair in the data, including DTW to IND (1), but none flew often enough under OO 4131 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SEA to SMF only.

One caution: this is a thin sample. 319 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 OO 4131

For a booking, OO 4131 has one of the better records a US domestic flight can show: 91.2% on time and 0.31% cancelled. That is a base rate, not a promise about any single day.

Where to go next

A flight number here means SkyWest 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