Carrier route record
DLORD→SLC
Delta Air Lines · Chicago to Salt Lake City
- Flights
- 1,011
- Period
- July 2025 to June 2026
- Share of route
- 32%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on ORD to SLC sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.6%. The late ones land close to two hours behind schedule. That rests on 1,011 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,069 at 71.7% on time.
The national on-time rate over the same period is 77.6%, so Delta on ORD to SLC runs 6 points behind the country as a whole. Across a thousand flights that is about 58 extra late arrivals.
Key figures
On time
71.8%
Arrivals under 15 minutes late, of 1,000 completed flights
Avg delay
105 min
Across delayed arrivals only, not all flights
Cancelled
0.79%
National rate is 1.81%
Whole route
68.8%
Every carrier on ORD to SLC, 3,198 flights
These figures cover 1,011 flights between July 2025 and June 2026. Beyond the headline rate, 11.1% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Delta against every carrier on ORD to SLC
Delta flew 1,011 of the 3,198 flights on ORD to SLC, about 32% of it. Its 71.8% on time is 3 points better than the route as a whole, which runs 68.8%. Ranked by on-time rate it is first of five carriers on the route, where the range runs from Delta at 71.8% to SkyWest at 56.2%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. United Airlines arrives on time 71.7% of the time; American Airlines manages 64.2%. Sample sizes sit next to every figure, because a two-point gap across 969 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines (this page) | 1,011 | 71.8% | 105 min | 0.79% | C+ |
| United Airlines | 1,069 | 71.7% | 64 min | 0.84% | C+ |
| American Airlines | 969 | 64.2% | 69 min | 1.96% | D |
| Envoy Airthin sample | 36 | 61.1% | 48 min | 0.00% | D+ |
| SkyWest Airlinesthin sample | 113 | 56.2% | 87 min | 0.88% | D+ |
United leads American by 8 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
Delta flight numbers on ORD to SLC
Departure window
When Delta runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 22 points, against 8 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am271 flights76.8%
- 8am–11am94 flights85.1%
- 11am–2pm89 flights70.5%
- 2pm–5pm211 flights74.3%
- 5pm–8pm345 flights63.2%
- 8pm–5am1 flights—
Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 63.2% on time, against 85.1% for the 8am–11am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5pm–8pm window is the busiest, with 345 flights scheduled in it.
Across the year
Delta on ORD to SLC through the year
December is the weak month at 54.1% on time, against 83.0% in October. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. October was the busiest month here, with 88 flights.
Across the week, Tuesday is the strongest day at 77.9% on time and Wednesday the weakest at 68.1%. 10 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Delta runs late on this route
One category carries most of the weight here. Carrier accounts for 47% of the 30,000 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.
- 47%Carrier
- 26%Late-arriving aircraft
- 14%National Airspace System
- 14%Extreme weather
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 monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.2 times the usual weather exposure. The split is drawn from 29,598 reported delay minutes.
The largest share of delay minutes, 47%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 14,000 of the 30,000 delay minutes reported here.
Cancellations are rare at 0.79%, 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 stage length
What a delay here costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 11.1% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
The 1,250 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 76.8% on time across 1,010 flights, 5 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 5 points of difference.
One caution: this is a thin sample. 1,011 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 Delta on ORD to SLC
Put together: treat all of this as provisional. 1,011 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 71.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,000 completed flights over 12 months sit behind that.
Related
Where to go next
- ORD to SLC, every carrier
- Delta on SLC to ORD, the return leg
- United Airlines on ORD to SLC71.7%
- American Airlines on ORD to SLC64.2%
- SkyWest Airlines on ORD to SLC56.2%
- Delta Air Lines network-wide record
- Chicago O'Hare International (ORD) delay statistics
- Salt Lake City International (SLC) delay statistics
- How often a connection fails at the major US hubs
- The best time of day to fly, according to 7.04 million flight records
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.