Flight number record

OO 4131

SkyWest Airlines · Seattle to Sacramento

Route: SEA → SMF
Departs: 19:45
Flights: 328
Period: September 2025 to August 2026

Historical statistics for September 2025 to August 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 11 points better than the national rate of 77.3%. When something does go wrong the average delay runs a little over an hour. That rests on 328 flights, with a median arrival 13 minutes early.

Set against the rest of the country, OO 4131's record is 11 points better than the US average of 77.3%. That gap is worth roughly 111 fewer late arrivals for every thousand flights.

On time

88.4%

Arrivals under 15 minutes late, of 327 completed flights

Avg delay

71 min

Across delayed arrivals only, not all flights

Cancelled

0.30%

National rate is 1.89%

1 hour+ late

2.8%

National rate is 8.3%

These figures cover 328 flights between September 2025 and August 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.

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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 328 flights, with 19:50 (57 flights) and 20:25 (56 flights) next.

Departs 19:4562 flights18.9%
Departs 19:5057 flights17.4%
Departs 20:2556 flights17.1%

Scale runs 0% to 100%.

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 68.0%, and OO 4131 runs 20 points better at 88.4%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

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Against the route

OO 4131 next to SEA to SMF

Every carrier on SEA to SMF combined arrived on time 82.1% of the time across 4,387 flights, so OO 4131 is 6 points ahead of it. SkyWest flew 1,839 flights on the same city pair under all its flight numbers, including this one, and those ran 89.1% on time. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 10 points.

OO 4131 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 4131thin sample	328	88.4%	71 min	0.30%	A+
All SkyWest Airlines on SEA–SMF	1,839	89.1%	63 min	0.27%	A+
All carriers on SEA–SMF	4,387	82.1%	51 min	0.39%	B+
SkyWest Airlines, whole network	855,406	78.7%	88 min	1.79%	B

Across the year

OO 4131 quarter by quarter

OO 4131 did not run the same all year. Its best quarter was Jan–Mar 2026 at 95.0% on time and its weakest Jul–Sep 2026 at 74.2%, a swing of 21 points on roughly 82 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.

Jul–Sep 202517 flights—
Oct–Dec 202577 flights88.3%
Jan–Mar 202681 flights95.0%
Apr–Jun 202691 flights90.1%
Jul–Sep 202662 flights74.2%

Scale runs 65% 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 77.1%. Each day rests on about 47 flights, so a gap of 21 points is worth noticing but could still narrow in another year.

Arrival by arrival

How late OO 4131 runs when it is late

OO 4131 often beats the schedule: 148 of 327 completed flights, 45%, arrived 15 minutes or more early. The 38 late arrivals split 16 under half an hour, 13 between 30 and 60 minutes, and 9 an hour or more.

15+ min early148 flights45.3%
Within 15 min141 flights43.1%
15–29 min late16 flights4.9%
30–59 min late13 flights4.0%
1–2 hours late5 flights1.5%
2+ hours late4 flights1.2%

Scale runs 0% to 100%.

Share of 327 completed flights by arrival against schedule.

5 of 36 late departures made up the time and arrived on time, 14% of them. 7 flights left on time and still arrived late.

The worst days

Worst days for OO 4131

The latest arrival of the period was on 2 August 2026, 11 hours 3 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). Three of the five worst days fell in August 2026.

The latest arrivals of OO 4131 in the period
Date	Arrived late by	Largest filed cause
2 August 2026	11 hours 3 minutes	Carrier
17 May 2026	4 hours 51 minutes	Carrier
16 July 2026	3 hours 20 minutes	Extreme weather
7 August 2026	2 hours 32 minutes	Carrier
14 August 2026	1 hour 59 minutes	Carrier

Delay causes

Why OO 4131 runs late

Carrier accounts for 80% of the 2,682 delay minutes carriers reported here, and the remaining four split what is left.

Carrier
80%
Extreme weather
15%
National Airspace System
4%
Security
1%

Extreme weather accounts for 15% 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 quarterly figures above are the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.6 times the usual weather exposure. The split is drawn from 2,682 delay minutes reported on OO 4131.

Cancellations are rare at 0.30%, below the national 1.89% 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 2.8% land an hour or more behind schedule, against 8.3% 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.

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. 328 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: 88.4% on time and 0.30% 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, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures