Carrier performance at one airport
DL→SLC
Delta Air Lines at Salt Lake City International
- Departures
- 54,749
- Period
- September 2025 to August 2026
- Routes
- 25
- Rank here
- #2 of 8
Delta Air Lines at Salt Lake City lands a B+, 6 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 54,749 flights, of which SkyWest Airlines flew 36,308 at 89.9% on time.
Measured against the airport rather than the country, Delta Air Lines runs about a point behind the 84.2% weighted average across all carriers at SLC. That is the comparison worth making: every operator here works the same runways, the same airspace and the same weather.
Key figures
On time
83.2%
54,146 completed departures
Avg delay
60 min
Across delayed flights only
Cancelled
0.80%
At SLC, this carrier only
Rank here
#2
Of 8 carriers clearing the floor at SLC
These figures cover 55,000 flights between September 2025 and August 2026. The median arrival is 8 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.
Against the competition
Every carrier at SLC, ranked
The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 89.9% of the time; JetBlue Airways manages 71.9%. Sample sizes sit next to every figure, because a two-point gap across 584 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlines | 36,308 | 89.9% | 68 min | 0.41% | A+ |
| Delta Air Lines (this page) | 54,749 | 83.2% | 60 min | 0.80% | B+ |
| Frontier Airlines | 3,572 | 80.3% | 86 min | 1.40% | B |
| United Airlines | 4,850 | 80.3% | 79 min | 1.09% | B |
| American Airlines | 4,660 | 79.5% | 108 min | 2.17% | B |
| Southwest Airlines | 11,193 | 77.6% | 49 min | 0.54% | B+ |
| Alaska Airlines | 1,733 | 76.1% | 50 min | 1.33% | B |
| JetBlue Airways | 584 | 71.9% | 83 min | 5.31% | C− |
JetBlue Airways cancels 5.3% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.
Route by route
Where Delta Air Lines flies from SLC
Delta Air Lines operates 25 routes out of SLC with enough volume to report. Route records inside one carrier at one airport still spread widely, because a short shuttle and a transcontinental have very different exposure to a late inbound.
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SLC to ATL · Atlanta | 2,968 | 86.5% | 65 min | 0.57% | A+ |
| SLC to LAX · Los Angeles | 2,459 | 83.5% | 52 min | 0.53% | B+ |
| SLC to SEA · Seattle | 2,234 | 82.7% | 53 min | 0.49% | B+ |
| SLC to SAN · San Diego | 1,738 | 82.2% | 54 min | 0.92% | B+ |
| SLC to LAS · Las Vegas | 1,716 | 79.0% | 56 min | 0.64% | B+ |
| SLC to SFO · San Francisco | 1,712 | 61.6% | 52 min | 0.93% | D+ |
| SLC to PHX · Phoenix | 1,707 | 87.6% | 56 min | 0.53% | A+ |
| SLC to DEN · Denver | 1,697 | 79.8% | 64 min | 0.18% | B+ |
| SLC to PDX · Portland | 1,695 | 87.9% | 53 min | 1.42% | A |
| SLC to MSP · Minneapolis | 1,609 | 86.4% | 56 min | 0.31% | A+ |
| SLC to SNA · Santa Ana | 1,606 | 83.0% | 62 min | 0.50% | B+ |
| SLC to JFK · New York | 1,539 | 83.2% | 66 min | 1.95% | B |
| SLC to DTW · Detroit | 1,528 | 88.2% | 60 min | 0.13% | A+ |
| SLC to SMF · Sacramento | 1,503 | 86.4% | 66 min | 1.20% | A |
| SLC to DFW · Dallas-Fort Worth | 1,458 | 81.6% | 64 min | 1.23% | B |
| SLC to MCO · Orlando | 1,409 | 83.1% | 57 min | 0.71% | B+ |
| SLC to BOI · Boise | 1,219 | 84.0% | 61 min | 1.07% | B |
| SLC to BOS · Boston | 1,083 | 82.7% | 59 min | 1.29% | B |
| SLC to AUS · Austin | 1,072 | 83.2% | 62 min | 0.65% | B+ |
| SLC to IAH · Houston | 1,016 | 83.1% | 77 min | 0.20% | B+ |
| SLC to SAT · San Antonio | 1,013 | 84.5% | 62 min | 0.79% | B+ |
| SLC to ORD · Chicago | 1,013 | 75.4% | 68 min | 1.09% | B |
| SLC to MCI · Kansas City | 1,005 | 85.4% | 56 min | 0.90% | A+ |
| SLC to STL · St. Louis | 981 | 83.7% | 58 min | 0.61% | B+ |
| SLC to GEG · Spokane | 974 | 81.1% | 72 min | 0.62% | B+ |
Flight by flight
Delta Air Lines flight numbers from SLC
114 Delta Air Lines flight numbers leaving SLC flew their main route often enough to have a record of their own. Grouped by destination.
- DL 835to ATL 09:5583.6%
- DL 875to ATL 15:3581.8%
- DL 885to ATL 11:0080.6%
- DL 897to ATL 08:1092.0%
- DL 905to ATL 17:5584.8%
- DL 906to ATL 13:2084.1%
- DL 907to ATL 07:0094.8%
- DL 912to ATL 23:3587.0%
- DL 2728to AUS 17:4580.2%
- DL 1340to BIL 21:0579.7%
- DL 2214to BNA 09:2589.2%
- DL 2317to BNA 17:4581.2%
- DL 1744to BOI 08:1590.2%
- DL 2111to BOI 22:5079.1%
- DL 657to BOS 09:3581.2%
- DL 696to BOS 23:3191.2%
- DL 702to BOS 17:1576.3%
- DL 339to BUR 20:5083.0%
- DL 2079to BWI 23:4078.3%
- DL 2855to CLE 17:2579.3%
- DL 2230to CMH 17:3578.3%
- DL 2273to CVG 09:4092.2%
- DL 2291to CVG 17:3086.6%
- DL 1553to DEN 10:1578.9%
- DL 1586to DEN 18:3068.3%
- DL 1623to DEN 13:2085.3%
- DL 1667to DEN 20:5979.7%
- DL 2796to DFW 17:3577.9%
- DL 2798to DFW 07:4586.2%
- DL 2800to DFW 09:5083.6%
- DL 2236to DTW 09:4293.4%
- DL 2244to DTW 13:5588.4%
- DL 2255to DTW 18:2879.0%
- DL 2289to DTW 06:0093.7%
- DL 2033to EWR 10:2581.3%
- DL 2038to EWR 23:3885.7%
- DL 1464to FCA 21:3082.3%
- DL 1466to GEG 22:5980.6%
- DL 316to HNL 11:4580.1%
- DL 847to IAD 17:3580.7%
- DL 2502to IAH 07:4589.0%
- DL 2514to IAH 17:3578.2%
- DL 2608to IDA 21:3081.4%
- DL 2228to IND 17:5081.4%
- DL 2282to JAC 11:1085.3%
- DL 671to JFK 14:3579.0%
- DL 697to JFK 17:2580.3%
- DL 705to JFK 23:5986.5%
- DL 1659to LAS 11:3574.9%
- DL 1662to LAS 22:5079.6%
- DL 1672to LAS 15:4572.9%
- DL 1698to LAS 07:5093.3%
- DL 829to LAX 11:3086.5%
- DL 841to LAX 15:0078.1%
- DL 1087to LAX 07:4591.1%
- DL 1095to LAX 09:2591.1%
- DL 1142to LAX 20:4573.7%
- DL 1161to LAX 17:1081.4%
- DL 2882to MCI 09:5588.7%
- DL 2993to MCI 20:5082.9%
- DL 2032to MCO 09:2583.6%
- DL 2056to MCO 17:2581.8%
- DL 2515to MEM 13:5084.2%
- DL 2040to MIA 23:5588.1%
- DL 2619to MKE 17:4580.7%
- DL 1723to MSO 22:4583.7%
- DL 2916to MSP 07:4591.8%
- DL 2924to MSP 11:1087.6%
- DL 2935to MSP 17:2580.1%
- DL 2936to MSP 14:0086.2%
- DL 2100to MSY 09:2587.2%
- DL 1614to ONT 22:5988.5%
- DL 2247to ORD 08:2085.1%
- DL 2377to ORD 14:4068.2%
- DL 2413to ORD 17:4571.1%
- DL 1209to PDX 11:2087.5%
- DL 1244to PDX 15:0087.8%
- DL 1373to PDX 22:5086.2%
- DL 2022to PHL 11:2583.7%
- DL 1431to PHX 11:2584.6%
- DL 1447to PHX 07:4594.7%
- DL 1496to PHX 22:4587.1%
- DL 1738to PHX 15:2884.6%
- DL 1409to RDU 17:5083.4%
- DL 1607to RNO 22:5985.2%
- DL 1177to SAN 07:4592.8%
- DL 1202to SAN 22:4581.9%
- DL 1210to SAN 15:0074.8%
- DL 1252to SAN 17:1079.9%
- DL 1296to SAN 11:1081.0%
- DL 2797to SAT 20:5083.6%
- DL 3123to SAT 09:5083.9%
- DL 871to SEA 17:1080.3%
- DL 2817to SEA 15:1577.3%
- DL 2874to SEA 07:4592.6%
- DL 2921to SEA 13:2084.0%
- DL 2995to SEA 11:3087.1%
- DL 2998to SEA 22:4590.0%
- DL 902to SFO 11:0059.8%
- DL 1088to SFO 15:0063.0%
- DL 1091to SFO 22:4565.3%
- DL 2762to SFO 20:5953.2%
- DL 1272to SJC 22:5082.8%
- DL 1342to SMF 15:2081.8%
- DL 1367to SMF 08:0592.6%
- DL 1423to SMF 11:1585.2%
- DL 1582to SMF 22:5989.0%
- DL 1189to SNA 11:2077.5%
- DL 1198to SNA 08:0088.8%
- DL 1277to SNA 15:1581.1%
- DL 1304to SNA 20:5584.5%
- DL 2455to STL 09:4089.8%
- DL 2666to STL 20:5079.8%
- DL 2077to TPA 23:5586.7%
Departure window
Best time of day for this operation
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 55,000 flights.
- 5am–8am3,112 flights90.0%
- 8am–11am11,423 flights87.2%
- 11am–2pm10,834 flights83.0%
- 2pm–5pm7,392 flights80.4%
- 5pm–8pm9,390 flights80.1%
- 8pm–5am12,598 flights82.2%
Scale runs 70% to 95%.
Book the early departure. Flights leaving between 5am–8am arrive on time 90.0% of the time, against 80.1% for the evening window. That is 10 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 12,598 flights scheduled in it.
Across the year
Seasonal pattern
August is the worst month at 76.5% on time, 11 points below September, the best at 87.2%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. July was the busiest month here, with 4,810 flights.
Delay causes
What holds this operation up
- 51%Carrier
- 22%National Airspace System
- 22%Late-arriving aircraft
- 5%Extreme weather
- 0%Security
The largest share of delay minutes, 51%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 279,000 of the 544,000 delay minutes reported here. The split is drawn from 544,167 reported delay minutes.
Cancellations are rare at 0.80%, below the national 1.89% 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.
5.0% 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.
54,749 flights sit behind these numbers, which is a large enough sample that the headline rate is not moving on noise. Where a sub-group falls below 30 flights the site shows a dash instead of a percentage.
Put together: take the 5am–8am departure, avoid August if the dates are flexible, and if two carriers are within a few dollars of each other, SkyWest is the one with the record behind it. None of that guarantees an on-time arrival; it moves the odds by 18 points, which is the most any booking decision can do. 54,146 completed flights over 12 months sit behind that.
Common questions
Delta Air Lines at SLC
How often is Delta Air Lines at SLC delayed?
About one flight in six arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 16.8% of the 54,749 flights in this analysis, against 22.7% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on Delta Air Lines at SLC?
SkyWest Airlines leads at 89.9% on time across 36,308 flights. JetBlue Airways is at the other end on 71.9%, a gap of 18 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on Delta Air Lines at SLC?
The 5am–8am departure window is the strongest at 90.0% on time. The 5pm–8pm window is the weakest at 80.1%, 10 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are August delays on Delta Air Lines at SLC?
August is the weakest month at 76.5% on time, compared with 87.2% in September. Across the year that is 11 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- Delta Air Lines network-wide record
- Salt Lake City International (SLC) all carriers
- SLC to ATL route record86.5%
- SLC to LAX route record83.5%
- SLC to SEA route record82.7%
- SLC to SAN route record82.2%
- Do airlines run better at their own hubs?
- Denver, Salt Lake City, Phoenix and Las Vegas: the Mountain West hubs
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.