Flight number record
UA 356
United Airlines · Chicago to Atlanta
- Route
- ORD → ATL
- Departs
- 14:30
- Flights
- 358
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s UA 356, check with United Airlines.
UA 356 sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 358 flights, with a median arrival 2 minutes early.
Key figures
On time
74.2%
Arrivals under 15 minutes late, of 349 completed flights
Avg delay
63 min
Across delayed arrivals only, not all flights
Cancelled
1.96%
National rate is 1.81%
1 hour+ late
9.2%
National rate is 8.1%
These figures cover 358 flights between July 2025 and June 2026. Beyond the headline rate, 9.2% 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.
Schedule
When UA 356 flies
UA 356 flies ORD to ATL without a single fixed slot. Its most common scheduled departure was 14:30, used on 130 of 358 flights, with 14:25 (89 flights) and 14:20 (43 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 14:30130 flights36.3%
- Departs 14:2589 flights24.9%
- Departs 14:2043 flights12.0%
Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 14:30 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 72.4%, and UA 356 runs level with that at 74.2%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
Against the route
UA 356 next to ORD to ATL
Every carrier on ORD to ATL combined arrived on time 75.0% of the time across 6,409 flights, so UA 356 is about level with it. United flew 1,611 flights on the same city pair under all its flight numbers, including this one, and those ran 74.7% on time. Across its whole network United Airlines managed 79.0%, which this flight trails by 5 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 356thin sample | 358 | 74.2% | 63 min | 1.96% | C |
| All United Airlines on ORD–ATL | 1,611 | 74.7% | 68 min | 1.12% | C |
| All carriers on ORD–ATL | 6,409 | 75.0% | 81 min | 2.26% | B |
| United Airlines, whole network | 821,041 | 79.0% | 72 min | 1.01% | B |
Across the year
UA 356 quarter by quarter
Quarter by quarter UA 356 held fairly steady: 75.3% in Jul–Sep 2025, 72.1% in Oct–Dec 2025, 75.0% in Jan–Mar 2026 and 74.4% in Apr–Jun 2026. A spread of 3 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202592 flights75.3%
- Oct–Dec 202589 flights72.1%
- Jan–Mar 202686 flights75.0%
- Apr–Jun 202691 flights74.4%
Scale runs 65% to 80%. Rows with fewer than 30 flights show a dash.
By weekday, UA 356 did best on Tuesday at 90.0% on time and worst on Sunday at 66.7%. Each day rests on about 51 flights, so a gap of 23 points is worth noticing but could still narrow in another year.
Delay causes
Why UA 356 runs late
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 5,627 reported delay minutes.
- 38%Late-arriving aircraft
- 31%Carrier
- 26%National Airspace System
- 5%Extreme weather
38% 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 5,627 reported delay minutes here, that single category outweighs weather by 7 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 5,627 delay minutes reported on UA 356.
Cancellations sit at 1.96% against a national 1.81%, which is ordinary. Diversions add another 0.56%.
Connections and routes
What a delay on this flight costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.2% 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 606 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 same number turns up on five other city pairs in the data, including PHX to ORD (136), SJC to ORD (74) and ONT to ORD (49), but none flew often enough under UA 356 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to ORD to ATL only.
One caution: this is a thin sample. 358 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 UA 356
For a booking, read UA 356 as 74.2% on time with 1.96% cancelled over 358 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- ORD to ATL, every carrier and departure
- ATL to ORD, the return direction
- Delta Air Lines 1264 on the same route91.1%
- Delta Air Lines 1247 on the same route87.2%
- Delta Air Lines 1147 on the same route79.9%
- Delta Air Lines 1178 on the same route87.1%
- Frontier Airlines 1596 on the same route74.8%
- Delta Air Lines 2738 on the same route65.4%
- Chicago O'Hare International (ORD) delay statistics
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- United Airlines on-time record
- Every United Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means United Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
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.