Carrier route record
UASMF→ORD
United Airlines · Sacramento to Chicago
- Flights
- 987
- Period
- July 2025 to June 2026
- Share of route
- 75%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on SMF to ORD lands a B, 2 points better than the national rate of 77.6%. About one flight in five 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 987 flights, with a median arrival 5 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate United on SMF 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
79.5%
Arrivals under 15 minutes late, of 970 completed flights
Avg delay
69 min
Across delayed arrivals only, not all flights
Cancelled
1.01%
National rate is 1.81%
Whole route
76.9%
Every carrier on SMF to ORD, 1,324 flights
These figures cover 987 flights between July 2025 and June 2026. The median arrival is 5 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.
Carrier by carrier
United against every carrier on SMF to ORD
United flew 987 of the 1,324 flights on SMF to ORD, most of the route. Its 79.5% on time is 3 points better than the route as a whole, which runs 76.9%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from United at 79.5% to American at 69.1%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines (this page) | 987 | 79.5% | 69 min | 1.01% | B |
| American Airlinesthin sample | 337 | 69.1% | 97 min | 1.19% | C |
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 25 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am325 flights88.6%
- 8am–11am253 flights85.1%
- 11am–2pm2 flights—
- 2pm–5pm223 flights63.1%
- 5pm–8pm—
- 8pm–5am184 flights76.1%
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 88.6% of the time, against 63.1% for the afternoon window. That is 25 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 325 flights scheduled in it.
Across the year
United on SMF to ORD through the year
July is the worst month at 50.6% on time, 40 points below February, the best at 91.1%. 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. May was the busiest month here, with 93 flights.
Across the week, Thursday is the strongest day at 86.0% on time and Sunday the weakest at 73.2%. 13 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 43% of the 14,000 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.
- 43%National Airspace System
- 35%Late-arriving aircraft
- 21%Carrier
- 1%Extreme weather
35% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 14,000 reported delay minutes here, that single category outweighs weather by 29 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 13,656 reported delay minutes.
43% 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 5,846 minutes out of 14,000, against a national NAS share of 21%.
Cancellations sit at 1.01% against a national 1.81%, which is ordinary. Diversions add another 0.71%.
Connections and stage length
What a delay here costs
6.2% 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.
At 1,781 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 68.3% on time across 988 flights, 11 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 11 points of difference.
One caution: this is a thin sample. 987 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 SMF to ORD
Put together: treat all of this as provisional. 987 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 79.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 970 completed flights over 12 months sit behind that.
Related
Where to go next
- SMF to ORD, every carrier
- United on ORD to SMF, the return leg
- American Airlines on SMF to ORD69.1%
- United Airlines network-wide record
- Sacramento International (SMF) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- Why the first flight of the morning is statistically safest
- 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.