Flight number record
OO 3721
SkyWest Airlines · Salt Lake City to Eugene
- Route
- SLC → EUG
- Departs
- 22:45
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 3721, 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 3721 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 15 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 365 flights, with a median arrival 11 minutes early.
Set against the rest of the country, OO 3721's record is 15 points better than the US average of 77.3%. That gap is worth roughly 148 fewer late arrivals for every thousand flights.
Key figures
On time
92.1%
Arrivals under 15 minutes late, of 365 completed flights
Avg delay
58 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.89%
1 hour+ late
2.7%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. The median arrival is 11 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 3721 flies
OO 3721 flies SLC to EUG without a single fixed slot. Its most common scheduled departure was 22:45, used on 135 of 365 flights, with 22:55 (69 flights) and 21:50 (61 flights) next.
- Departs 22:45135 flights37.0%
- Departs 22:5569 flights18.9%
- Departs 21:5061 flights16.7%
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 22:45 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.1%, and OO 3721 runs 22 points better at 92.1%. 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 3721 next to SLC to EUG
Every carrier on SLC to EUG combined arrived on time 90.9% of the time across 800 flights, so OO 3721 is about level with it. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 13 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 3721 | 365 | 92.1% | 58 min | 0.00% | A+ |
| All SkyWest Airlines on SLC–EUG | 800 | 90.9% | 54 min | 0.00% | A+ |
| All carriers on SLC–EUG | 800 | 90.9% | 54 min | 0.00% | A+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 3721 quarter by quarter
OO 3721 did not run the same all year. Its best quarter was Oct–Dec 2025 at 97.8% on time and its weakest Jul–Sep 2026 at 80.6%, a swing of 17 points on roughly 73 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202530 flights96.7%
- Oct–Dec 202592 flights97.8%
- Jan–Mar 202690 flights94.4%
- Apr–Jun 202691 flights90.1%
- Jul–Sep 202662 flights80.6%
Scale runs 70% to 100%.
By weekday, OO 3721 did best on Monday at 96.2% on time and worst on Thursday at 82.7%. 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 3721 runs when it is late
OO 3721 often beats the schedule: 130 of 365 completed flights, 36%, arrived 15 minutes or more early. The 29 late arrivals split 10 under half an hour, 9 between 30 and 60 minutes, and 10 an hour or more.
- 15+ min early130 flights35.6%
- Within 15 min206 flights56.4%
- 15–29 min late10 flights2.7%
- 30–59 min late9 flights2.5%
- 1–2 hours late7 flights1.9%
- 2+ hours late3 flights0.8%
Scale runs 0% to 100%.
Share of 365 completed flights by arrival against schedule.
6 of 29 late departures made up the time and arrived on time, 21% of them. Only 6 left on time and still arrived late.
The worst days
Worst days for OO 3721
The latest arrival of the period was on 30 November 2025, 2 hours 57 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 |
|---|---|---|
| 30 November 2025 | 2 hours 57 minutes | Carrier |
| 22 March 2026 | 2 hours 35 minutes | Carrier |
| 30 August 2026 | 2 hours 7 minutes | Carrier |
| 30 September 2025 | 1 hour 46 minutes | Carrier |
| 16 July 2026 | 1 hour 40 minutes | Extreme weather |
Delay causes
Why OO 3721 runs late
Carrier accounts for 81% of the 1,688 delay minutes carriers reported here, and the remaining four split what is left.
- 81%Carrier
- 12%Extreme weather
- 6%National Airspace System
Extreme weather accounts for 12% 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 2.1 times the usual weather exposure. The split is drawn from 1,688 delay minutes reported on OO 3721.
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 2.7% 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.
The 618 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.
Every one of the 365 flights under OO 3721 in the data flew SLC to EUG. 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 3721
For a booking, OO 3721 has one of the better records a US domestic flight can show: 92.1% on time and 0.00% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- SLC to EUG, every carrier and departure
- EUG to SLC, the return direction
- SkyWest Airlines 4135 on the same route91.5%
- 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.