Flight number record

OO 4019

SkyWest Airlines · Hailey to Salt Lake City

Route: SUN → SLC
Departs: 12:38
Flights: 361
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s OO 4019, 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 4019 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 14 points better than the national rate of 77.6%. When something does go wrong the average delay runs close to two hours. That rests on 361 flights, with a median arrival 13 minutes early.

Set against the rest of the country, OO 4019's record is 14 points better than the US average of 77.6%. That gap is worth roughly 138 fewer late arrivals for every thousand flights.

On time

91.4%

Arrivals under 15 minutes late, of 359 completed flights

Avg delay

105 min

Across delayed arrivals only, not all flights

Cancelled

0.55%

National rate is 1.81%

1 hour+ late

4.5%

National rate is 8.1%

These figures cover 361 flights between July 2025 and June 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.

Schedule

When OO 4019 flies

OO 4019 flies SUN to SLC without a single fixed slot. Its most common scheduled departure was 12:38, used on 66 of 361 flights, with 12:40 (52 flights) and 13:06 (40 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 12:3866 flights18.3%
Departs 12:4052 flights14.4%
Departs 13:0640 flights11.1%

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 12:38 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and OO 4019 runs 13 points better at 91.4%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

OO 4019 next to SUN to SLC

Every carrier on SUN to SLC combined arrived on time 94.6% of the time across 1,078 flights, so OO 4019 is 3 points behind it. Across its whole network SkyWest Airlines managed 79.0%, which this flight beats by 12 points.

OO 4019 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 4019thin sample	361	91.4%	105 min	0.55%	A+
All SkyWest Airlines on SUN–SLC	1,078	94.6%	119 min	0.74%	A+
All carriers on SUN–SLC	1,078	94.6%	119 min	0.74%	A+
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	B

Across the year

OO 4019 quarter by quarter

Quarter by quarter OO 4019 held fairly steady: 94.6% in Jul–Sep 2025, 89.9% in Oct–Dec 2025, 91.1% in Jan–Mar 2026 and 89.8% in Apr–Jun 2026. A spread of 5 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights94.6%
Oct–Dec 202591 flights89.9%
Jan–Mar 202690 flights91.1%
Apr–Jun 202688 flights89.8%

Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, OO 4019 did best on Tuesday at 98.1% on time and worst on Wednesday at 84.0%. Each day rests on about 52 flights, so a gap of 14 points is worth noticing but could still narrow in another year.

Delay causes

Why OO 4019 runs late

One category carries most of the weight here. Carrier accounts for 74% of the 3,258 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
74%
Extreme weather
22%
National Airspace System
4%

Extreme weather accounts for 22% 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 3.6 times the usual weather exposure. The split is drawn from 3,258 delay minutes reported on OO 4019.

Cancellations are rare at 0.55%, 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 4.5% 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.

Every one of the 361 flights under OO 4019 in the data flew SUN to SLC. The number was not reused on any other city pair, which makes this a clean record of one route.

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.

What to do with this

Booking OO 4019

For a booking, OO 4019 has one of the better records a US domestic flight can show: 91.4% 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures