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DelayAtlas

Flight number record

UA 1983

United Airlines · Miami to Chicago

Route
MIA → ORD
Departs
12:30
Flights
308
Period
September 2025 to August 2026
B+GRADE

Historical statistics for September 2025 to August 2026, not live status. For today’s UA 1983, check with United Airlines.

UA 1983 lands a B+, 4 points better than the national rate of 77.3%. 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 rests on 308 flights, with a median arrival 9 minutes early.

Key figures

On time

80.9%

Arrivals under 15 minutes late, of 303 completed flights

Avg delay

77 min

Across delayed arrivals only, not all flights

Cancelled

0.32%

National rate is 1.89%

1 hour+ late

7.9%

National rate is 8.3%

These figures cover 308 flights between September 2025 and August 2026. The median arrival is 9 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.

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Schedule

When UA 1983 flies

UA 1983 flies MIA to ORD without a single fixed slot. Its most common scheduled departure was 12:30, used on 82 of 308 flights, with 12:23 (53 flights) and 12:18 (37 flights) next.

  • Departs 12:3082 flights26.6%
  • Departs 12:2353 flights17.2%
  • Departs 12:1837 flights12.0%

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 12:30 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and UA 1983 runs 3 points better at 80.9%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.

Against the route

UA 1983 next to MIA to ORD

Every carrier on MIA to ORD combined arrived on time 71.1% of the time across 4,464 flights, so UA 1983 is 10 points ahead of it. United flew 1,087 flights on the same city pair under all its flight numbers, including this one, and those ran 69.7% on time. Across its whole network United Airlines managed 78.8%, which this flight beats by 2 points.

UA 1983 against its route and carrier
Compared withFlightsOn timeAvg delayCancelledGrade
UA 1983thin sample30880.9%77 min0.32%B+
All United Airlines on MIA–ORD1,08769.7%85 min1.01%C
All carriers on MIA–ORD4,46471.1%79 min1.93%C
United Airlines, whole network830,82578.8%73 min1.02%B

Across the year

UA 1983 quarter by quarter

Quarter by quarter UA 1983 held fairly steady: 76.2% in Oct–Dec 2025, 79.7% in Jan–Mar 2026, 83.6% in Apr–Jun 2026 and 82.0% in Jul–Sep 2026. A spread of 7 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

  • Jul–Sep 202518 flights—
  • Oct–Dec 202585 flights76.2%
  • Jan–Mar 202681 flights79.7%
  • Apr–Jun 202662 flights83.6%
  • Jul–Sep 202662 flights82.0%

Scale runs 70% to 90%. Rows with fewer than 30 flights show a dash.

By weekday, UA 1983 did best on Saturday at 90.9% on time and worst on Sunday at 73.3%. Each day rests on about 44 flights, so a gap of 18 points is worth noticing but could still narrow in another year.

On-time rate by day of the week81.2Mon75.0Tue83.3Wed83.0Thu78.7Fri90.9Sat73.3Sun
Monday: 81.2 percent on time. Tuesday: 75.0 percent on time. Wednesday: 83.3 percent on time. Thursday: 83.0 percent on time. Friday: 78.7 percent on time. Saturday: 90.9 percent on time. Sunday: 73.3 percent on time

Arrival by arrival

How late UA 1983 runs when it is late

UA 1983 often beats the schedule: 114 of 303 completed flights, 38%, arrived 15 minutes or more early. The 58 late arrivals split 23 under half an hour, 11 between 30 and 60 minutes, and 24 an hour or more.

  • 15+ min early114 flights37.6%
  • Within 15 min131 flights43.2%
  • 15–29 min late23 flights7.6%
  • 30–59 min late11 flights3.6%
  • 1–2 hours late12 flights4.0%
  • 2+ hours late12 flights4.0%

Scale runs 0% to 100%.

Share of 303 completed flights by arrival against schedule.

9 of 48 late departures made up the time and arrived on time, 19% of them. In the other direction, 19 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 ORD.

The worst days

Worst days for UA 1983

The latest arrival of the period was on 25 January 2026, 9 hours 9 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On three of the five worst days the largest share was filed as national airspace system delay.

The latest arrivals of UA 1983 in the period
DateArrived late byLargest filed cause
25 January 20269 hours 9 minutesLate-arriving aircraft
3 November 20255 hours 31 minutesLate-arriving aircraft
6 March 20264 hours 15 minutesNational Airspace System
27 July 20263 hours 34 minutesNational Airspace System
11 August 20263 hours 14 minutesNational Airspace System

Delay causes

Why UA 1983 runs late

National Airspace System accounts for 48% of the 4,487 delay minutes carriers reported here, and the remaining four split what is left.

  • National Airspace System
    48%
  • Late-arriving aircraft
    36%
  • Carrier
    16%

36% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 4,487 reported delay minutes here, that single category outweighs weather by 36 to one. The split is drawn from 4,487 delay minutes reported on UA 1983.

Cancellations are rare at 0.32%, 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

7.9% of arrivals land an hour or more late, close to the national 8.3%, so 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.

The 1,197 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 three other city pairs in the data, including ORD to IAH (32), ORD to BOS (18) and ORD to LGA (14), but none flew often enough under UA 1983 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to MIA to ORD only.

One caution: this is a thin sample. 308 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 1983

For a booking, read UA 1983 as 80.9% on time with 0.32% cancelled over 308 flights. Those are rates from the past twelve months, not a forecast for any particular day.

Related

Where to go next

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.