Carrier route record
DLSLC→ORD
Delta Air Lines · Salt Lake City to Chicago
- Flights
- 1,010
- 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 SLC to ORD lands a B+, about a point worse than the national rate of 77.6%. About one flight in four arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 1,010 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,069 at 75.4% on time.
The US average over the same twelve months is 77.6%, so there is little to separate Delta on SLC to ORD from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
76.8%
Arrivals under 15 minutes late, of 994 completed flights
Avg delay
70 min
Across delayed arrivals only, not all flights
Cancelled
0.69%
National rate is 1.81%
Whole route
75.3%
Every carrier on SLC to ORD, 3,198 flights
These figures cover 1,010 flights between July 2025 and June 2026. Beyond the headline rate, 8.2% 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 SLC to ORD
Delta flew 1,010 of the 3,198 flights on SLC to ORD, about 32% of it. Its 76.8% on time is 2 points better than the route as a whole, which runs 75.3%. Ranked by on-time rate it is number two of five carriers on the route, where the range runs from SkyWest at 77.0% to Envoy at 61.1%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: about a point separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 115 | 77.0% | 122 min | 1.74% | B |
| Delta Air Lines (this page) | 1,010 | 76.8% | 70 min | 0.69% | B+ |
| United Airlines | 1,069 | 75.4% | 89 min | 1.12% | B |
| American Airlines | 968 | 74.0% | 106 min | 1.86% | C |
| Envoy Airthin sample | 36 | 61.1% | 80 min | 0.00% | D+ |
No carrier stands out. United tops the table at 75.4%, about a point clear of the bottom, which is inside the range this kind of sample moves year to year.
Flight by flight
Delta flight numbers on SLC to ORD
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 19 points, against about a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am117 flights85.5%
- 8am–11am243 flights85.5%
- 11am–2pm51 flights84.3%
- 2pm–5pm246 flights66.8%
- 5pm–8pm353 flights73.5%
- 8pm–5am—
Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 85.5% of the time, against 66.8% for the afternoon window. That is 19 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 353 flights scheduled in it.
Across the year
Delta on SLC to ORD through the year
July is the worst month at 66.7% on time, 20 points below August, the best at 87.1%. 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. October was the busiest month here, with 88 flights.
Across the week, Saturday is the strongest day at 84.0% on time and Monday the weakest at 71.2%. 13 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. National Airspace System accounts for 49% of the 16,000 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.
- 49%National Airspace System
- 35%Carrier
- 13%Late-arriving aircraft
- 3%Extreme weather
The largest share of delay minutes, 35%, 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 5,634 of the 16,000 delay minutes reported here. The split is drawn from 16,128 reported delay minutes.
49% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 7,880 minutes out of 16,000, against a national NAS share of 21%.
Cancellations are rare at 0.69%, 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
8.2% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.
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 71.8% on time across 1,011 flights, 5 points below 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. 1,010 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 SLC to ORD
Put together: treat all of this as provisional. 1,010 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 76.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 994 completed flights over 12 months sit behind that.
Related
Where to go next
- SLC to ORD, every carrier
- Delta on ORD to SLC, the return leg
- SkyWest Airlines on SLC to ORD77.0%
- United Airlines on SLC to ORD75.4%
- American Airlines on SLC to ORD74.0%
- Delta Air Lines network-wide record
- Salt Lake City International (SLC) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
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.