Carrier route record
UASLC→ORD
United Airlines · Salt Lake City to Chicago
- Flights
- 1,069
- Period
- July 2025 to June 2026
- Share of route
- 33%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on SLC to ORD sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 1,069 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 1,010 at 76.8% on time.
The US average over the same twelve months is 77.6%, so there is little to separate United 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
75.4%
Arrivals under 15 minutes late, of 1,051 completed flights
Avg delay
89 min
Across delayed arrivals only, not all flights
Cancelled
1.12%
National rate is 1.81%
Whole route
75.3%
Every carrier on SLC to ORD, 3,198 flights
These figures cover 1,069 flights between July 2025 and June 2026. Beyond the headline rate, 9.5% 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
United against every carrier on SLC to ORD
United flew 1,069 of the 3,198 flights on SLC to ORD, about 33% of it. Its 75.4% on time is about level with the route as a whole at 75.3%. Ranked by on-time rate it is number three 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: 3 points 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 | 1,010 | 76.8% | 70 min | 0.69% | B+ |
| United Airlines (this page) | 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. Delta tops the table at 76.8%, 3 points clear of the bottom, which is inside the range this kind of sample moves year to year.
Flight by flight
United flight numbers on SLC to ORD
Departure window
When United runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 26 points, against 3 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am117 flights88.0%
- 8am–11am268 flights87.5%
- 11am–2pm364 flights74.2%
- 2pm–5pm320 flights61.8%
- 5pm–8pm—
- 8pm–5am—
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 88.0% of the time, against 61.8% for the afternoon window. That is 26 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 364 flights scheduled in it.
Across the year
United on SLC to ORD through the year
January is the weak month at 63.0% on time, against 84.6% in May. 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. March was the busiest month here, with 121 flights.
Across the week, Tuesday is the strongest day at 79.1% on time and Sunday the weakest at 72.7%. 6 points is a smaller lever than departure hour, but it is free.
Delay causes
Why United runs late on this route
One category carries most of the weight here. National Airspace System accounts for 50% of the 23,000 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.
- 50%National Airspace System
- 22%Late-arriving aircraft
- 16%Carrier
- 12%Extreme weather
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 monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.0 times the usual weather exposure. The split is drawn from 22,956 reported delay minutes.
50% 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 11,000 minutes out of 23,000, against a national NAS share of 21%.
Cancellations sit at 1.12% against a national 1.81%, which is ordinary. Diversions add another 0.56%.
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. 9.5% 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 71.7% on time across 1,069 flights, 4 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 4 points of difference.
One caution: this is a thin sample. 1,069 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 United on SLC to ORD
Put together: treat all of this as provisional. 1,069 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 75.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,051 completed flights over 12 months sit behind that.
Related
Where to go next
- SLC to ORD, every carrier
- United on ORD to SLC, the return leg
- SkyWest Airlines on SLC to ORD77.0%
- Delta Air Lines on SLC to ORD76.8%
- American Airlines on SLC to ORD74.0%
- United Airlines 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
- How often a connection fails at the major US hubs
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.