Flight number record

OO 4312

SkyWest Airlines · Salt Lake City to Butte

Route: SLC → BTM
Departs: 15:40
Flights: 361
Period: September 2025 to August 2026

Historical statistics for September 2025 to August 2026, not live status. For today’s OO 4312, 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 4312 earns an A+. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 17 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 361 flights, with a median arrival 15 minutes early.

Set against the rest of the country, OO 4312's record is 17 points better than the US average of 77.3%. That gap is worth roughly 174 fewer late arrivals for every thousand flights.

On time

94.7%

Arrivals under 15 minutes late, of 357 completed flights

Avg delay

61 min

Across delayed arrivals only, not all flights

Cancelled

0.55%

National rate is 1.89%

1 hour+ late

2.2%

National rate is 8.3%

These figures cover 361 flights between September 2025 and August 2026. The median arrival is 15 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 4312 flies

OO 4312 flies SLC to BTM without a single fixed slot. Its most common scheduled departure was 15:40, used on 244 of 361 flights, with 15:30 (88 flights) next.

Departs 15:40244 flights67.6%
Departs 15:3088 flights24.4%

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 15:40 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 71.9%, and OO 4312 runs 23 points better at 94.7%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

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Against the route

OO 4312 next to SLC to BTM

Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 16 points.

OO 4312 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 4312thin sample	361	94.7%	61 min	0.55%	A+
All SkyWest Airlines on SLC–BTMthin sample	361	94.7%	61 min	0.55%	A+
All carriers on SLC–BTMthin sample	361	94.7%	61 min	0.55%	A+
SkyWest Airlines, whole network	855,406	78.7%	88 min	1.79%	B

Across the year

OO 4312 quarter by quarter

Quarter by quarter OO 4312 held fairly steady: 93.3% in Jul–Sep 2025, 98.9% in Oct–Dec 2025, 97.8% in Jan–Mar 2026, 91.0% in Apr–Jun 2026 and 90.3% in Jul–Sep 2026. A spread of 9 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202530 flights93.3%
Oct–Dec 202589 flights98.9%
Jan–Mar 202689 flights97.8%
Apr–Jun 202691 flights91.0%
Jul–Sep 202662 flights90.3%

Scale runs 80% to 100%.

By weekday, OO 4312 ranged from 90.2% on Sunday to 98.1% on Friday. With about 52 flights behind each day, a spread of 8 points is inside normal variation, so the day you fly is not worth changing for this flight.

Arrival by arrival

How late OO 4312 runs when it is late

OO 4312 often beats the schedule: 185 of 357 completed flights, 52%, arrived 15 minutes or more early. The 19 late arrivals split 7 under half an hour, 4 between 30 and 60 minutes, and 8 an hour or more.

15+ min early185 flights51.8%
Within 15 min153 flights42.9%
15–29 min late7 flights2.0%
30–59 min late4 flights1.1%
1–2 hours late7 flights2.0%
2+ hours late1 flights0.3%

Scale runs 0% to 100%.

Share of 357 completed flights by arrival against schedule.

5 of 22 late departures made up the time and arrived on time, 23% of them. Only 2 left on time and still arrived late.

The worst days

Worst days for OO 4312

The latest arrival of the period was on 4 October 2025, 3 hours 12 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on five of the five worst days.

The latest arrivals of OO 4312 in the period
Date	Arrived late by	Largest filed cause
4 October 2025	3 hours 12 minutes	Carrier
3 August 2026	1 hour 50 minutes	Carrier
29 September 2025	1 hour 23 minutes	Carrier
30 May 2026	1 hour 22 minutes	Carrier
25 June 2026	1 hour 22 minutes	Carrier

Delay causes

Why OO 4312 runs late

Carrier accounts for 84% of the 1,153 delay minutes carriers reported here, and the remaining four split what is left.

Carrier
84%
Extreme weather
13%
National Airspace System
3%

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 2.2 times the usual weather exposure. The split is drawn from 1,153 delay minutes reported on OO 4312.

Cancellations are rare at 0.55%, 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 2.2% 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.

OO 4312 is not only a SLC to BTM flight. It also flew BTM to SLC (361 flights, 94.7% 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. 361 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 4312
Also flown as	Flights	On time	Avg delay	Cancelled	Grade
BTM to SLCthin sample	361	94.7%	189 min	0.55%	A+

What to do with this

Booking OO 4312

For a booking, OO 4312 has one of the better records a US domestic flight can show: 94.7% on time and 0.55% 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