Flight number record

OO 4039

SkyWest Airlines · Seattle to Bozeman

Route: SEA → BZN
Departs: 19:59
Flights: 250
Period: September 2025 to August 2026

Historical statistics for September 2025 to August 2026, not live status. For today’s OO 4039, 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 4039 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 roughly 55 minutes on average. That rests on 250 flights, with a median arrival 12 minutes early.

Set against the rest of the country, OO 4039's record is 5 points better than the US average of 77.3%. That gap is worth roughly 54 fewer late arrivals for every thousand flights.

On time

82.7%

Arrivals under 15 minutes late, of 249 completed flights

Avg delay

53 min

Across delayed arrivals only, not all flights

Cancelled

0.40%

National rate is 1.89%

1 hour+ late

4.0%

National rate is 8.3%

These figures cover 250 flights between September 2025 and August 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.

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Schedule

When OO 4039 flies

OO 4039 flies SEA to BZN without a single fixed slot. Its most common scheduled departure was 19:59, used on 92 of 250 flights, with 19:45 (69 flights) and 19:50 (52 flights) next.

Departs 19:5992 flights36.8%
Departs 19:4569 flights27.6%
Departs 19:5052 flights20.8%

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 19:59 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and OO 4039 runs 15 points better at 82.7%. 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 4039 next to SEA to BZN

Every carrier on SEA to BZN combined arrived on time 81.6% of the time across 1,566 flights, so OO 4039 is about level with it. SkyWest flew 937 flights on the same city pair under all its flight numbers, including this one, and those ran 84.2% on time. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 4 points.

OO 4039 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 4039thin sample	250	82.7%	53 min	0.40%	B+
All SkyWest Airlines on SEA–BZN	937	84.2%	54 min	0.21%	B+
All carriers on SEA–BZN	1,566	81.6%	52 min	0.45%	B+
SkyWest Airlines, whole network	855,406	78.7%	88 min	1.79%	B

Across the year

OO 4039 quarter by quarter

OO 4039 did not run the same all year. Its best quarter was Jan–Mar 2026 at 88.6% on time and its weakest Jul–Sep 2026 at 74.2%, a swing of 14 points on roughly 83 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.

Oct–Dec 20259 flights—
Jan–Mar 202689 flights88.6%
Apr–Jun 202690 flights81.1%
Jul–Sep 202662 flights74.2%

Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, OO 4039 did best on Saturday at 97.3% on time and worst on Sunday at 73.0%. Each day rests on about 36 flights, so a gap of 24 points is worth noticing but could still narrow in another year.

Arrival by arrival

How late OO 4039 runs when it is late

OO 4039 often beats the schedule: 99 of 249 completed flights, 40%, arrived 15 minutes or more early. The 43 late arrivals split 12 under half an hour, 21 between 30 and 60 minutes, and 10 an hour or more.

15+ min early99 flights39.8%
Within 15 min107 flights43.0%
15–29 min late12 flights4.8%
30–59 min late21 flights8.4%
1–2 hours late7 flights2.8%
2+ hours late3 flights1.2%

Scale runs 0% to 100%.

Share of 249 completed flights by arrival against schedule.

7 of 45 late departures made up the time and arrived on time, 16% of them. 5 flights left on time and still arrived late.

The worst days

Worst days for OO 4039

The latest arrival of the period was on 21 August 2026, 3 hours 48 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 4039 in the period
Date	Arrived late by	Largest filed cause
21 August 2026	3 hours 48 minutes	Carrier
29 July 2026	2 hours 59 minutes	Carrier
15 March 2026	2 hours 27 minutes	Carrier
28 May 2026	1 hour 57 minutes	National Airspace System
24 May 2026	1 hour 40 minutes	Carrier

Delay causes

Why OO 4039 runs late

Carrier accounts for 60% of the 2,279 delay minutes carriers reported here, and the remaining four split what is left.

Carrier
60%
Extreme weather
23%
National Airspace System
17%

Extreme weather accounts for 23% 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 3.8 times the usual weather exposure. The split is drawn from 2,279 delay minutes reported on OO 4039.

Cancellations are rare at 0.40%, 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 4.0% 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 543 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 MSP to RIC (3), but none flew often enough under OO 4039 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SEA to BZN only.

One caution: this is a thin sample. 250 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 4039

For a booking, read OO 4039 as 82.7% on time with 0.40% cancelled over 250 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