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DelayAtlas

Flight number record

OO 4317

SkyWest Airlines · Salt Lake City to Elko

Route
SLC → EKO
Departs
21:30
Flights
364
Period
July 2025 to June 2026
A+GRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s OO 4317, 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 4317 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 77.6%. When something does go wrong the average delay runs about 4.3 hours. That rests on 364 flights, with a median arrival 18 minutes early.

Set against the rest of the country, OO 4317's record is 17 points better than the US average of 77.6%. That gap is worth roughly 171 fewer late arrivals for every thousand flights.

Key figures

On time

94.7%

Arrivals under 15 minutes late, of 360 completed flights

Avg delay

256 min

Across delayed arrivals only, not all flights

Cancelled

0.82%

National rate is 1.81%

1 hour+ late

3.1%

National rate is 8.1%

These figures cover 364 flights between July 2025 and June 2026. The median arrival is 18 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 4317 flies

OO 4317 is scheduled to leave Salt Lake City (SLC) at 21:30 local time and reach Elko (EKO) at 21:34. That slot held for 346 of the 364 scheduled departures in the data, so the figures below describe one steady operation rather than a number that moved around the clock.

  • Departs 21:30346 flights95.1%

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 21:30 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.5%, and OO 4317 runs 24 points better at 94.7%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

Against the route

OO 4317 next to SLC to EKO

Every carrier on SLC to EKO combined arrived on time 93.5% of the time across 575 flights, so OO 4317 is about level with it. Across its whole network SkyWest Airlines managed 79.0%, which this flight beats by 16 points.

OO 4317 against its route and carrier
Compared withFlightsOn timeAvg delayCancelledGrade
OO 4317thin sample36494.7%256 min0.82%A+
All SkyWest Airlines on SLC–EKO57593.5%163 min0.70%A+
All carriers on SLC–EKO57593.5%163 min0.70%A+
SkyWest Airlines, whole network852,93579.0%88 min1.77%B

Across the year

OO 4317 quarter by quarter

Quarter by quarter OO 4317 held fairly steady: 97.8% in Jul–Sep 2025, 96.7% in Oct–Dec 2025, 95.4% in Jan–Mar 2026 and 88.9% in Apr–Jun 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 202592 flights97.8%
  • Oct–Dec 202591 flights96.7%
  • Jan–Mar 202690 flights95.4%
  • Apr–Jun 202691 flights88.9%

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

By weekday, OO 4317 ranged from 90.2% on Friday to 100.0% on Sunday. With about 52 flights behind each day, a spread of 10 points is inside normal variation, so the day you fly is not worth changing for this flight.

On-time rate by day of the week98.0Mon92.5Tue94.2Wed94.1Thu90.2Fri94.2Sat100.0Sun
Monday: 98.0 percent on time. Tuesday: 92.5 percent on time. Wednesday: 94.2 percent on time. Thursday: 94.1 percent on time. Friday: 90.2 percent on time. Saturday: 94.2 percent on time. Sunday: 100.0 percent on time

Delay causes

Why OO 4317 runs late

One category carries most of the weight here. Carrier accounts for 81% of the 4,863 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
    81%
  • Extreme weather
    18%
  • National Airspace System
    0%

Extreme weather accounts for 18% 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 2.9 times the usual weather exposure. The split is drawn from 4,863 delay minutes reported on OO 4317.

Cancellations are rare at 0.82%, 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 3.1% 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 364 flights under OO 4317 in the data flew SLC to EKO. 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. 364 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 4317

For a booking, OO 4317 has one of the better records a US domestic flight can show: 94.7% on time and 0.82% cancelled. That is a base rate, not a promise about any single day.

Related

Where to go next

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.