Flight number record

OO 3740

SkyWest Airlines · Boise to Seattle

Route: BOI → SEA
Departs: 09:00
Flights: 346
Period: September 2025 to August 2026

Historical statistics for September 2025 to August 2026, not live status. For today’s OO 3740, 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 3740 lands a B+, 5 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That rests on 346 flights, with a median arrival 14 minutes early.

Set against the rest of the country, OO 3740's record is 5 points better than the US average of 77.3%. That gap is worth roughly 48 fewer late arrivals for every thousand flights.

On time

82.1%

Arrivals under 15 minutes late, of 346 completed flights

Avg delay

82 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.89%

1 hour+ late

7.5%

National rate is 8.3%

These figures cover 346 flights between September 2025 and August 2026. The median arrival is 14 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 3740 flies

OO 3740 flies BOI to SEA without a single fixed slot. Its most common scheduled departure was 09:00, used on 146 of 346 flights, with 08:42 (57 flights) and 08:59 (53 flights) next.

Departs 09:00146 flights42.2%
Departs 08:4257 flights16.5%
Departs 08:5953 flights15.3%

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 09:00 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and OO 3740 runs level with that at 82.1%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

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Against the route

OO 3740 next to BOI to SEA

Every carrier on BOI to SEA combined arrived on time 84.9% of the time across 3,730 flights, so OO 3740 is 3 points behind it. SkyWest flew 2,754 flights on the same city pair under all its flight numbers, including this one, and those ran 85.9% on time. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 3 points.

OO 3740 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 3740thin sample	346	82.1%	82 min	0.00%	B+
All SkyWest Airlines on BOI–SEA	2,754	85.9%	61 min	0.29%	A+
All carriers on BOI–SEA	3,730	84.9%	56 min	0.40%	B+
SkyWest Airlines, whole network	855,406	78.7%	88 min	1.79%	B

Across the year

OO 3740 quarter by quarter

Quarter by quarter OO 3740 held fairly steady: 83.3% in Jul–Sep 2025, 80.0% in Oct–Dec 2025, 81.9% in Jan–Mar 2026, 85.7% in Apr–Jun 2026 and 79.0% in Jul–Sep 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 202530 flights83.3%
Oct–Dec 202580 flights80.0%
Jan–Mar 202683 flights81.9%
Apr–Jun 202691 flights85.7%
Jul–Sep 202662 flights79.0%

Scale runs 70% to 90%.

By weekday, OO 3740 did best on Tuesday at 88.0% on time and worst on Saturday at 74.5%. Each day rests on about 49 flights, so a gap of 14 points is worth noticing but could still narrow in another year.

Arrival by arrival

How late OO 3740 runs when it is late

OO 3740 often beats the schedule: 170 of 346 completed flights, 49%, arrived 15 minutes or more early. The 62 late arrivals split 8 under half an hour, 28 between 30 and 60 minutes, and 26 an hour or more.

15+ min early170 flights49.1%
Within 15 min114 flights32.9%
15–29 min late8 flights2.3%
30–59 min late28 flights8.1%
1–2 hours late15 flights4.3%
2+ hours late11 flights3.2%

Scale runs 0% to 100%.

Share of 346 completed flights by arrival against schedule.

Time lost at the gate mostly stays lost. Of 31 departures that left 15 minutes late or more, only 3 made it up before arrival. In the other direction, 34 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at SEA.

The worst days

Worst days for OO 3740

The latest arrival of the period was on 29 June 2026, 7 hours 51 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.

The latest arrivals of OO 3740 in the period
Date	Arrived late by	Largest filed cause
29 June 2026	7 hours 51 minutes	Carrier
21 November 2025	7 hours 32 minutes	Extreme weather
14 May 2026	5 hours 29 minutes	Carrier
15 March 2026	4 hours 10 minutes	Carrier
25 July 2026	3 hours 2 minutes	Carrier

Delay causes

Why OO 3740 runs late

Carrier accounts for 73% of the 5,088 delay minutes carriers reported here, and the remaining four split what is left.

Carrier
73%
National Airspace System
14%
Extreme weather
13%

Extreme weather accounts for 13% 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 2.1 times the usual weather exposure. The split is drawn from 5,088 delay minutes reported on OO 3740.

Cancellations are rare at 0.00%, below the national 1.89% 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 routes

What a delay on this flight costs

7.5% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last an hour and a half, which a normal layover absorbs.

The same number turns up on one other city pair in the data, including SLC to SBA (16), but none flew often enough under OO 3740 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to BOI to SEA only.

One caution: this is a thin sample. 346 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 3740

For a booking, read OO 3740 as 82.1% on time with 0.00% cancelled over 346 flights. Those are rates from the past twelve months, not a forecast for any particular 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