Flight number record
OO 4019
SkyWest Airlines · Hailey to Salt Lake City
- Route
- SUN → SLC
- Departs
- 13:06
- Flights
- 361
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 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 13 points better than the national rate of 77.3%. When something does go wrong the average delay runs an hour and a half. That rests on 361 flights, with a median arrival 13 minutes early.
Set against the rest of the country, OO 4019's record is 13 points better than the US average of 77.3%. That gap is worth roughly 130 fewer late arrivals for every thousand flights.
Key figures
On time
90.3%
Arrivals under 15 minutes late, of 359 completed flights
Avg delay
92 min
Across delayed arrivals only, not all flights
Cancelled
0.55%
National rate is 1.89%
1 hour+ late
5.0%
National rate is 8.3%
These figures cover 361 flights between September 2025 and August 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.
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Schedule
When OO 4019 flies
OO 4019 flies SUN to SLC without a single fixed slot. Its most common scheduled departure was 13:06, used on 65 of 361 flights, with 13:10 (57 flights) and 12:40 (52 flights) next.
- Departs 13:0665 flights18.0%
- Departs 13:1057 flights15.8%
- Departs 12:4052 flights14.4%
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 13:06 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and OO 4019 runs 12 points better at 90.3%. 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 4019 next to SUN to SLC
Every carrier on SUN to SLC combined arrived on time 93.8% of the time across 1,078 flights, so OO 4019 is 4 points behind it. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 12 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 4019thin sample | 361 | 90.3% | 92 min | 0.55% | A+ |
| All SkyWest Airlines on SUN–SLC | 1,078 | 93.8% | 112 min | 0.74% | A+ |
| All carriers on SUN–SLC | 1,078 | 93.8% | 112 min | 0.74% | A+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 4019 quarter by quarter
Quarter by quarter OO 4019 held fairly steady: 96.7% in Jul–Sep 2025, 89.9% in Oct–Dec 2025, 91.1% in Jan–Mar 2026, 89.8% in Apr–Jun 2026 and 87.1% in Jul–Sep 2026. A spread of 10 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202530 flights96.7%
- Oct–Dec 202591 flights89.9%
- Jan–Mar 202690 flights91.1%
- Apr–Jun 202688 flights89.8%
- Jul–Sep 202662 flights87.1%
Scale runs 80% to 100%.
By weekday, OO 4019 did best on Tuesday at 98.0% 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.
Arrival by arrival
How late OO 4019 runs when it is late
OO 4019 often beats the schedule: 157 of 359 completed flights, 44%, arrived 15 minutes or more early. When OO 4019 is late it tends to be very late: 18 of its 35 late arrivals were an hour or more behind, and 9 were two hours or more.
- 15+ min early157 flights43.7%
- Within 15 min167 flights46.5%
- 15–29 min late10 flights2.8%
- 30–59 min late7 flights1.9%
- 1–2 hours late9 flights2.5%
- 2+ hours late9 flights2.5%
Scale runs 0% to 100%.
Share of 359 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 33 departures that left 15 minutes late or more, only 2 made it up before arrival. Only 4 left on time and still arrived late.
The worst days
Worst days for OO 4019
The latest arrival of the period was on 5 March 2026, 9 hours 16 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.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 5 March 2026 | 9 hours 16 minutes | Carrier |
| 14 August 2026 | 3 hours 41 minutes | Carrier |
| 8 August 2026 | 3 hours 32 minutes | Carrier |
| 21 December 2025 | 2 hours 53 minutes | Extreme weather |
| 4 January 2026 | 2 hours 31 minutes | Carrier |
Delay causes
Why OO 4019 runs late
Carrier accounts for 75% of the 3,212 delay minutes carriers reported here, and the remaining four split what is left.
- 75%Carrier
- 22%Extreme weather
- 3%National Airspace System
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 3,212 delay minutes reported on OO 4019.
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
5.0% 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.
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: 90.3% on time and 0.55% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- SUN to SLC, every carrier and departure
- SLC to SUN, the return direction
- SkyWest Airlines 4037 on the same route98.1%
- Salt Lake City International (SLC) delay statistics
- SkyWest Airlines on-time record
- Every SkyWest Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Worst months to fly in the US, ranked by the data
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 ; recomputed monthly. How this data is collected.