Flight number record

OO 3918

SkyWest Airlines · Portland to Seattle

Route: PDX → SEA
Departs: 17:45
Flights: 324
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s OO 3918, 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 3918 earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs roughly 55 minutes. That rests on 324 flights, with a median arrival 12 minutes early.

Set against the rest of the country, OO 3918's record is 9 points better than the US average of 77.6%. That gap is worth roughly 88 fewer late arrivals for every thousand flights.

On time

86.4%

Arrivals under 15 minutes late, of 323 completed flights

Avg delay

53 min

Across delayed arrivals only, not all flights

Cancelled

0.31%

National rate is 1.81%

1 hour+ late

2.5%

National rate is 8.1%

These figures cover 324 flights between July 2025 and June 2026. The median arrival is 12 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 3918 flies

OO 3918 flies PDX to SEA without a single fixed slot. Its most common scheduled departure was 17:45, used on 66 of 324 flights, with 17:50 (57 flights) and 17:15 (56 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 17:4566 flights20.4%
Departs 17:5057 flights17.6%
Departs 17:1556 flights17.3%

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 17:45 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and OO 3918 runs 18 points better at 86.4%. 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 3918 next to PDX to SEA

Every carrier on PDX to SEA combined arrived on time 84.8% of the time across 4,938 flights, so OO 3918 is 2 points ahead of it. SkyWest flew 3,501 flights on the same city pair under all its flight numbers, including this one, and those ran 85.2% on time. Across its whole network SkyWest Airlines managed 79.0%, which this flight beats by 7 points.

OO 3918 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 3918thin sample	324	86.4%	53 min	0.31%	A+
All SkyWest Airlines on PDX–SEA	3,501	85.2%	59 min	0.54%	A+
All carriers on PDX–SEA	4,938	84.8%	55 min	0.65%	B+
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	B

Across the year

OO 3918 quarter by quarter

OO 3918 did not run the same all year. Its best quarter was Oct–Dec 2025 at 93.7% on time and its weakest Apr–Jun 2026 at 76.1%, a swing of 18 points on roughly 81 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 202592 flights89.1%
Oct–Dec 202579 flights93.7%
Jan–Mar 202686 flights84.7%
Apr–Jun 202667 flights76.1%

Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, OO 3918 did best on Saturday at 100.0% on time and worst on Thursday at 76.1%. Each day rests on about 46 flights, so a gap of 24 points is worth noticing but could still narrow in another year.

Delay causes

Why OO 3918 runs late

One category carries most of the weight here. Carrier accounts for 44% of the 2,321 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
44%
Extreme weather
32%
National Airspace System
22%
Security
1%

Extreme weather accounts for 32% 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 5.2 times the usual weather exposure. The split is drawn from 2,321 delay minutes reported on OO 3918.

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 2.5% 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.

OO 3918 is not only a PDX to SEA flight. It also flew SEA to PDX (323 flights, 84.5% on time) often enough to be scored on its own. Airlines attach one number to several legs of an aircraft's day, and each leg keeps its own record here, so check which city pair is on your booking before reading a rate.

One caution: this is a thin sample. 324 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.

Other routes flown as OO 3918
Also flown as	Flights	On time	Avg delay	Cancelled	Grade
SEA to PDXthin sample	323	84.5%	41 min	0.31%	B+

What to do with this

Booking OO 3918

For a booking, OO 3918 has one of the better records a US domestic flight can show: 86.4% 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