Flight number record
OO 4148
SkyWest Airlines · Los Angeles to Boise
- Route
- LAX → BOI
- Departs
- 19:59
- Flights
- 255
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 4148, 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 4148 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 10 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 255 flights, with a median arrival 14 minutes early.
Set against the rest of the country, OO 4148's record is 10 points better than the US average of 77.3%. That gap is worth roughly 102 fewer late arrivals for every thousand flights.
Key figures
On time
87.5%
Arrivals under 15 minutes late, of 255 completed flights
Avg delay
62 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.89%
1 hour+ late
5.5%
National rate is 8.3%
These figures cover 255 flights between September 2025 and August 2026. The median arrival is 14 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 4148 flies
OO 4148 flies LAX to BOI without a single fixed slot. Its most common scheduled departure was 19:59, used on 57 of 255 flights, with 19:15 (38 flights) and 19:55 (31 flights) next.
- Departs 19:5957 flights22.4%
- Departs 19:1538 flights14.9%
- Departs 19:5531 flights12.2%
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 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 4148 runs 20 points better at 87.5%. 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 4148 next to LAX to BOI
Every carrier on LAX to BOI combined arrived on time 89.8% of the time across 1,356 flights, so OO 4148 is 2 points behind it. SkyWest flew 1,325 flights on the same city pair under all its flight numbers, including this one, and those ran 89.7% on time. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 9 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 4148thin sample | 255 | 87.5% | 62 min | 0.00% | A+ |
| All SkyWest Airlines on LAX–BOI | 1,325 | 89.7% | 74 min | 0.08% | A+ |
| All carriers on LAX–BOI | 1,356 | 89.8% | 74 min | 0.07% | A+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 4148 quarter by quarter
Quarter by quarter OO 4148 held fairly steady: 85.6% in Jan–Mar 2026, 91.2% in Apr–Jun 2026 and 85.5% in Jul–Sep 2026. A spread of 6 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Oct–Dec 202512 flights—
- Jan–Mar 202690 flights85.6%
- Apr–Jun 202691 flights91.2%
- Jul–Sep 202662 flights85.5%
Scale runs 75% to 95%. Rows with fewer than 30 flights show a dash.
By weekday, OO 4148 did best on Tuesday at 97.2% on time and worst on Friday at 80.6%. Each day rests on about 36 flights, so a gap of 17 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late OO 4148 runs when it is late
OO 4148 often beats the schedule: 122 of 255 completed flights, 48%, arrived 15 minutes or more early. The 32 late arrivals split 9 under half an hour, 9 between 30 and 60 minutes, and 14 an hour or more.
- 15+ min early122 flights47.8%
- Within 15 min101 flights39.6%
- 15–29 min late9 flights3.5%
- 30–59 min late9 flights3.5%
- 1–2 hours late11 flights4.3%
- 2+ hours late3 flights1.2%
Scale runs 0% to 100%.
Share of 255 completed flights by arrival against schedule.
7 of 38 late departures made up the time and arrived on time, 18% of them. Only 1 left on time and still arrived late.
The worst days
Worst days for OO 4148
The latest arrival of the period was on 23 December 2025, 2 hours 12 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 |
|---|---|---|
| 23 December 2025 | 2 hours 12 minutes | Carrier |
| 20 April 2026 | 2 hours 8 minutes | Carrier |
| 15 March 2026 | 2 hours | Carrier |
| 18 February 2026 | 1 hour 56 minutes | Extreme weather |
| 31 July 2026 | 1 hour 56 minutes | Carrier |
Delay causes
Why OO 4148 runs late
Carrier accounts for 82% of the 1,967 delay minutes carriers reported here, and the remaining four split what is left.
- 82%Carrier
- 14%Extreme weather
- 4%National Airspace System
Extreme weather accounts for 14% 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 2.3 times the usual weather exposure. The split is drawn from 1,967 delay minutes reported on OO 4148.
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
5.5% 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 about an hour, which a normal layover absorbs.
The 674 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 four other city pairs in the data, including SEA to SNA (65), SNA to SEA (65) and BUF to DTW (4), but none flew often enough under OO 4148 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to LAX to BOI only.
One caution: this is a thin sample. 255 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 4148
For a booking, OO 4148 has one of the better records a US domestic flight can show: 87.5% on time and 0.00% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- LAX to BOI, every carrier and departure
- BOI to LAX, the return direction
- Los Angeles International (LAX) 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.