Flight number record
UA 1398
United Airlines · Chicago to Atlanta
- Route
- ORD → ATL
- Departs
- 18:20
- Flights
- 292
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 1398, check with United Airlines.
UA 1398 earns a D+, which is as low as this site's scale goes for a reason. Only 56.2% of flights arrive inside the 15-minute window, 21 points worse than the national rate of 77.3%. Late arrivals average a little over an hour. Treat any tight connection here as a coin flip. That rests on 292 flights, with a median arrival 9 minutes late.
The national on-time rate over the same period is 77.3%, so UA 1398 runs 21 points behind the country as a whole. Across a thousand flights that is about 211 extra late arrivals.
Key figures
On time
56.2%
Arrivals under 15 minutes late, of 290 completed flights
Avg delay
74 min
Across delayed arrivals only, not all flights
Cancelled
0.68%
National rate is 1.89%
1 hour+ late
16.2%
National rate is 8.3%
These figures cover 292 flights between September 2025 and August 2026. Beyond the headline rate, 16.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When UA 1398 flies
UA 1398 flies ORD to ATL without a single fixed slot. Its most common scheduled departure was 18:20, used on 147 of 292 flights, with 18:10 (37 flights) next.
- Departs 18:20147 flights50.3%
- Departs 18:1037 flights12.7%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 18:20 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and UA 1398 runs 12 points worse at 56.2%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
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Against the route
UA 1398 next to ORD to ATL
Every carrier on ORD to ATL combined arrived on time 74.1% of the time across 6,495 flights, so UA 1398 is 18 points behind it. United flew 1,717 flights on the same city pair under all its flight numbers, including this one, and those ran 74.5% on time. Across its whole network United Airlines managed 78.8%, which this flight trails by 23 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1398thin sample | 292 | 56.2% | 74 min | 0.68% | D+ |
| All United Airlines on ORD–ATL | 1,717 | 74.5% | 67 min | 1.34% | C |
| All carriers on ORD–ATL | 6,495 | 74.1% | 81 min | 2.31% | C |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 1398 quarter by quarter
UA 1398 did not run the same all year. Its best quarter was Jul–Sep 2025 at 83.3% on time and its weakest Apr–Jun 2026 at 47.5%, a swing of 36 points on roughly 58 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202530 flights83.3%
- Oct–Dec 202573 flights56.2%
- Jan–Mar 202687 flights52.9%
- Apr–Jun 202641 flights47.5%
- Jul–Sep 202661 flights53.3%
Scale runs 40% to 90%.
By weekday, UA 1398 did best on Saturday at 69.0% on time and worst on Friday at 37.2%. Each day rests on about 42 flights, so a gap of 32 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 1398 runs when it is late
The 127 late arrivals split 43 under half an hour, 37 between 30 and 60 minutes, and 47 an hour or more.
- 15+ min early32 flights11.0%
- Within 15 min131 flights45.2%
- 15–29 min late43 flights14.8%
- 30–59 min late37 flights12.8%
- 1–2 hours late23 flights7.9%
- 2+ hours late24 flights8.3%
Scale runs 0% to 100%.
Share of 290 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 103 departures that left 15 minutes late or more, only 12 made it up before arrival. In the other direction, 36 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at ATL.
The worst days
Worst days for UA 1398
The latest arrival of the period was on 10 June 2026, 6 hours 49 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. Three of the five worst days fell in June 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 10 June 2026 | 6 hours 49 minutes | Late-arriving aircraft |
| 6 March 2026 | 5 hours 36 minutes | Late-arriving aircraft |
| 8 November 2025 | 5 hours 28 minutes | National Airspace System |
| 17 June 2026 | 5 hours 23 minutes | Late-arriving aircraft |
| 24 June 2026 | 4 hours 35 minutes | Extreme weather |
Delay causes
Why UA 1398 runs late
Late-arriving aircraft accounts for 54% of the 9,357 delay minutes carriers reported here, and the remaining four split what is left.
- 54%Late-arriving aircraft
- 22%National Airspace System
- 18%Carrier
- 6%Extreme weather
54% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 9,357 reported delay minutes here, that single category outweighs weather by 9 to one. The split is drawn from 9,357 delay minutes reported on UA 1398.
Cancellations are rare at 0.68%, below the national 1.89% 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 routes
What a delay on this flight costs
16.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection 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.
The same number turns up on seven other city pairs in the data, including COS to ORD (127), SNA to ORD (66) and IAH to PIT (32), but none flew often enough under UA 1398 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. 292 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 1398
For a booking, UA 1398 is a flight to put a long connection behind. 16.2% of its completed flights arrived an hour or more late, which a short layover will not absorb. If the onward flight is on a separate ticket, the risk sits with you.
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 route91.3%
- Delta Air Lines 1247 on the same route87.8%
- United Airlines 356 on the same route73.1%
- Delta Air Lines 1147 on the same route79.3%
- Delta Air Lines 1178 on the same route85.4%
- Frontier Airlines 1596 on the same route72.4%
- 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.