Flight profile · United Airlines
UA1983
Miami (MIA) to Chicago (ORD) · scheduled 12:30 PM – 2:55 PM
How UA1983 performs
953 operations, July 2023 – July 2026.
UA1983 arrived on time 81.9% of the time, against 74.3% for all MIA → ORD flights, so this departure is 7.6 percentage points better than the route as a whole. Against United Airlines’ own flights on this route it is 8.5 points better.
Source: US DOT Bureau of Transportation Statistics · 953 operations, July 2023 – July 2026 · If UA1983 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
Where UA1983 is right now
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Against the rest of the route
| Flight or route | On time | Cancelled | Median delay | Severe | Flights |
|---|---|---|---|---|---|
| UA1983 | 81.9% | 1.26% | -8 min | 7.7% | 953 |
| United Airlines on MIA → ORD | 73.4% | 1.10% | -3 min | 10.1% | 3,087 |
| All MIA → ORD flights | 74.3% | 1.31% | -6 min | 9.8% | 13,637 |
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026
Why UA1983 runs late
Where US DOT attributed the delay minutes on this flight.
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
crew, maintenance, boarding and fueling, all within the carrier’s control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for UA1983 on MIA → ORD. Only delays of 15 minutes or more are attributed.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
Does a late aircraft delay this flight?
How often the plane that flies UA1983 comes in late, and what that does to the departure.
The aircraft flying UA1983 came in 15 or more minutes late on 12% of the departures where its previous flight is known. There are not enough departures in both groups to say how the flight left after a late one and after an on-time one.
Each departure is matched to the flight the same aircraft flew into MIA just before it, using the tail number in the DOT file, 927 of 942 departures in all. A departure is left out when that flight is unknown, was cancelled or diverted, or the aircraft had sat for more than 12 hours. A flight the airline cancelled never left and is not in the count, and one flown by a substitute aircraft is matched to the aircraft that flew it, not to the one first planned.
Against the network at the same turn length
| Share of departures | Inbound landed 15+ late |
|---|---|
| UA1983 | 12% |
| Network, same turn | 17% |
The schedule leaves a normal turn: enough time to clean and board if the aircraft is on time, little to spare if it is not.
The network row is every flight with a scheduled turn of 60 to 89 minutes. How often UA1983’s aircraft landed 15 or more minutes late is lower than the network’s. There are not enough departures in both groups to compare how it left.
More: Which Flight Numbers Pay for a Late Aircraft lists the flight numbers that pass a late aircraft on.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
From pushback to gate
When it leaves MIA late, does that still matter by the time it reaches ORD?
UA1983 pushes back an average of 10.2 minutes late and reaches the gate at ORD an average of 5.1 minutes late. The 5.1 minutes between those two figures are slack the published schedule already carries, which is why a late pushback on this flight does not reliably become a late arrival. It spends 24.1 minutes on the taxiways at MIA, 1.3 minutes longer than a typical MIA departure in the same hour.
On arrival at ORD, UA1983 spends 14.9 min taxiing from touchdown to the gate — ground time a connecting passenger sits through before they can even leave the aircraft, on top of however late the flight itself ran. That is 2.9 minutes shorter than a typical ORD arrival (17.8 min).
Departure delay is averaged over every pushback and arrival delay over every completed arrival, so the two counts differ by the flights that never reached ORD. Taxi-out is gate to wheels up and sits inside the scheduled block rather than on top of it; the comparison is 14,602 departures from MIA scheduled in the clock hour UA1983 most often leaves in. Taxi-in is landing to gate, compared against every arrival FlyerIntel has on file at ORD (952,666 flights), not just UA1983’s own. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026
The hour it leaves MIA
Part of any flight’s record belongs to the clock rather than to the flight. UA1983 has one departure time, so this is what that time is worth.
On-time arrival rate. 14,602 departures from MIA are scheduled in the 12 PM–1 PM hour over the period, against 340,469 across the whole day.
UA1983 is scheduled out of MIA at 12:30 PM, in the 12 PM–1 PM bank. Departures from MIA in that hour arrive on time 75.0% of the time against 73.2% across the airport’s whole day, so the hour UA1983 leaves in is an ordinary one for MIA and explains nothing about its record either way.
The two airport figures cover every departure from MIA to every destination, so they describe the slot rather than this journey — the like-for-like comparison against the route is above. Hours are scheduled local, and a number whose schedule moved between banks inside the period has no single hour and is not described here at all. Why the hour matters.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Hours below 120 departures are not scored.
By day of week
Does UA1983 run worse on particular days?
Monday is historically the most reliable day and Sunday the least, a gap of 13.3 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Days with fewer than 120 operations are not scored.
Other routes UA1983 has flown
A flight number is a slot in a schedule, and carriers reassign it. These are the other city pairs this number served in the analysis period.
| Route | Operated | Flights | On time |
|---|---|---|---|
| ORD→IAH Chicago to Houston | June 27, 2024 – April 29, 2026 | 85 | — |
| ORD→LGA Chicago to New York | September 29, 2023 – January 4, 2026 | 16 | — |
| ORD→BOS Chicago to Boston | September 25, 2025 – October 24, 2025 | 18 | — |
| ORD→LAX Chicago to Los Angeles | May 23, 2024 – August 18, 2025 | 103 | 62.7% |
| LAX→TPA Los Angeles to Tampa | June 26, 2025 – August 18, 2025 | 54 | — |
| ORD→SNA Chicago to Santa Ana | February 13, 2025 – April 30, 2025 | 71 | — |
| ORD→EWR Chicago to Newark | December 19, 2024 – January 6, 2025 | 19 | — |
| ORD→SFO Chicago to San Francisco | March 7, 2024 – September 25, 2024 | 62 | — |
| SFO→MIA San Francisco to Miami | December 20, 2023 – September 25, 2024 | 39 | — |
| RDU→ORD Raleigh–Durham to Chicago | August 19, 2024 – September 25, 2024 | 35 | — |
| ORD→SYR Chicago to Syracuse | December 20, 2023 – January 8, 2024 | 16 | — |
Because the same number has served different journeys, the statistics above describe only the route UA1983 currently operates. Blending them would produce an average of two different flights.
When it goes wrong
The average describes a usual day. This is the day that ruins a connection.
38 min late
against a median of 8 min early
Percentiles over 953 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
Data and methodology
Calculated by FlyerIntel from 953 records of UA1983 operating MIA → ORD, published by the US DOT Bureau of Transportation Statistics. A flight counts as delayed when it arrives 15 or more minutes after schedule. Cancelled and diverted flights are excluded from the on-time rate and reported separately. Flight numbers are resolved as carrier plus number plus route, because the same number serves different routes over time.
Full methodology · Data sources · Report a problem
Related research: Most and Least Reliable Flight Numbers · The Delay You Inherit · Making Up Time in the Air
Analysis last recomputed