About 1 in 12 DL 4321 flights from Salt Lake City arrived 15+ minutes late, diverted or cancelled over the past year (8%); 0.0% were cancelled. The typical flight landed 12 minutes early.
DL 4321: SLC → SGU
Scheduled to leave Salt Lake City at 1:30 p.m. local time, operated by SkyWest as OO 4321. Over the past year it arrived on time 92% of the time (355 flights), in line with other DL flights on the route at that hour (92%). Last seen in the data Aug 31, 2026.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 53 | 94% |
| Tuesday | 51 | 94% |
| Wednesday | 51 | 94% |
| Thursday | 50 | 90% |
| Friday | 51 | 90% |
| Saturday | 48 | 90% |
| Sunday | 51 | 90% |
Why it was late
All flights SLC → SGU · Connecting off DL 4321? Check the risk
DL 4321: SGU → SLC
Scheduled to leave St. George at 3:20 p.m. local time, operated by SkyWest as OO 4321. Over the past year it arrived on time 87% of the time (353 flights), in line with other DL flights on the route at that hour (87%). Last seen in the data Aug 31, 2026.
Usually Delta Air Lines's last flight of the day from St. George to Salt Lake City (52% of days). Delta Air Lines's last SGU–SLC flight was cancelled 0.0% of the time, against 0.2% for its earlier ones. If it's cancelled, the next Delta Air Lines flight is usually around 5:50 a.m. the next morning.
Month by month
By day of week
| Day | Flights | On time |
|---|---|---|
| Monday | 53 | 87% |
| Tuesday | 51 | 94% |
| Wednesday | 50 | 88% |
| Thursday | 49 | 86% |
| Friday | 51 | 88% |
| Saturday | 48 | 83% |
| Sunday | 51 | 84% |
Why it was late
All flights SGU → SLC · Connecting off DL 4321? Check the risk
Questions
How often is DL 4321 from SLC to SGU late?
Delta Air Lines 4321 from Salt Lake City, UT to St. George, UT arrived 15 or more minutes late, was diverted or was cancelled on 8% of 355 scheduled flights between September 2025 and August 2026. 0.0% were cancelled.
How often is DL 4321 from SGU to SLC late?
Delta Air Lines 4321 from St. George, UT to Salt Lake City, UT arrived 15 or more minutes late, was diverted or was cancelled on 13% of 353 scheduled flights between September 2025 and August 2026. 0.0% were cancelled.
Flight numbers change. Figures cover flights with this airline, number and route only. "Likely range" is the 95% interval for the true on-time rate given the number of flights. This is history, not live status: check Delta Air Lines for today's flight. Method.