Flight number record
OO 4230
SkyWest Airlines · Grand Junction to Salt Lake City
- Route
- GJT → SLC
- Departs
- 07:40
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 4230, 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 4230 earns an A+. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 20 points better than the national rate of 77.3%. When something does go wrong the average delay runs close to two hours. That rests on 365 flights, with a median arrival 19 minutes early.
Set against the rest of the country, OO 4230's record is 20 points better than the US average of 77.3%. That gap is worth roughly 200 fewer late arrivals for every thousand flights.
Key figures
On time
97.3%
Arrivals under 15 minutes late, of 364 completed flights
Avg delay
103 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.89%
1 hour+ late
1.6%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. The median arrival is 19 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 4230 flies
OO 4230 flies GJT to SLC without a single fixed slot. Its most common scheduled departure was 07:40, used on 120 of 365 flights, with 07:45 (60 flights) and 05:55 (59 flights) next.
- Departs 07:40120 flights32.9%
- Departs 07:4560 flights16.4%
- Departs 05:5559 flights16.2%
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 07:40 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and OO 4230 runs 8 points better at 97.3%. 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 4230 next to GJT to SLC
Every carrier on GJT to SLC combined arrived on time 94.7% of the time across 584 flights, so OO 4230 is 3 points ahead of it. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 19 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 4230 | 365 | 97.3% | 103 min | 0.00% | A+ |
| All SkyWest Airlines on GJT–SLC | 584 | 94.7% | 64 min | 0.00% | A+ |
| All carriers on GJT–SLC | 584 | 94.7% | 64 min | 0.00% | A+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 4230 quarter by quarter
Quarter by quarter OO 4230 held fairly steady: 100.0% in Jul–Sep 2025, 97.8% in Oct–Dec 2025, 97.8% in Jan–Mar 2026, 95.6% in Apr–Jun 2026 and 96.7% in Jul–Sep 2026. A spread of 4 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202530 flights100.0%
- Oct–Dec 202592 flights97.8%
- Jan–Mar 202690 flights97.8%
- Apr–Jun 202691 flights95.6%
- Jul–Sep 202662 flights96.7%
Scale runs 85% to 100%.
By weekday, OO 4230 ranged from 92.3% on Friday to 100.0% on Thursday. 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 4230 runs when it is late
OO 4230 often beats the schedule: 247 of 364 completed flights, 68%, arrived 15 minutes or more early. When OO 4230 is late it tends to be very late: 6 of its 10 late arrivals were an hour or more behind, and 3 were two hours or more.
- 15+ min early247 flights67.9%
- Within 15 min107 flights29.4%
- 15–29 min late2 flights0.5%
- 30–59 min late2 flights0.5%
- 1–2 hours late3 flights0.8%
- 2+ hours late3 flights0.8%
Scale runs 0% to 100%.
Share of 364 completed flights by arrival against schedule.
Only 7 of 364 completed flights left 15 minutes late or more, too few to say how often the time is made up.
The worst days
Worst days for OO 4230
The latest arrival of the period was on 28 April 2026, 7 hours 1 minute 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.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 28 April 2026 | 7 hours 1 minute | Carrier |
| 28 November 2025 | 2 hours 25 minutes | Carrier |
| 3 June 2026 | 2 hours | Carrier |
| 6 July 2026 | 1 hour 41 minutes | Carrier |
| 26 August 2026 | 1 hour 9 minutes | Carrier |
Delay causes
Why OO 4230 runs late
Carrier accounts for 93% of the 1,033 delay minutes carriers reported here, and the remaining four split what is left.
- 93%Carrier
- 6%National Airspace System
- 1%Extreme weather
The largest share of delay minutes, 93%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 961 of the 1,033 delay minutes reported here. The split is drawn from 1,033 delay minutes reported on OO 4230.
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
Badly late arrivals are rare here: only 1.6% 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.
Every one of the 365 flights under OO 4230 in the data flew GJT 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. 365 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 4230
For a booking, OO 4230 has one of the better records a US domestic flight can show: 97.3% on time and 0.00% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- 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.