Flight number record

UA 1983

United Airlines · Miami to Chicago

Route: MIA → ORD
Departs: 12:23
Flights: 300
Period: July 2025 to June 2026

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

UA 1983 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 an hour and a half on average. That is a workable record, not a spotless one. That rests on 300 flights, with a median arrival 8 minutes early.

On time

79.4%

Arrivals under 15 minutes late, of 296 completed flights

Avg delay

87 min

Across delayed arrivals only, not all flights

Cancelled

0.33%

National rate is 1.81%

1 hour+ late

8.8%

National rate is 8.1%

These figures cover 300 flights between July 2025 and June 2026. Beyond the headline rate, 8.8% 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 1983 flies

UA 1983 flies MIA to ORD without a single fixed slot. Its most common scheduled departure was 12:23, used on 53 of 300 flights, with 12:20 (48 flights) and 12:27 (42 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 12:2353 flights17.7%
Departs 12:2048 flights16.0%
Departs 12:2742 flights14.0%

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 12:23 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and UA 1983 runs level with that at 79.4%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

UA 1983 next to MIA to ORD

Every carrier on MIA to ORD combined arrived on time 70.8% of the time across 4,447 flights, so UA 1983 is 9 points ahead of it. United flew 1,040 flights on the same city pair under all its flight numbers, including this one, and those ran 70.7% on time. Across its whole network United Airlines managed 79.0%, close to this flight's figure.

UA 1983 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 1983thin sample	300	79.4%	87 min	0.33%	B+
All United Airlines on MIA–ORD	1,040	70.7%	85 min	0.87%	C+
All carriers on MIA–ORD	4,447	70.8%	75 min	1.96%	C
United Airlines, whole network	821,041	79.0%	72 min	1.01%	B

Across the year

UA 1983 quarter by quarter

Quarter by quarter UA 1983 held fairly steady: 79.2% in Jul–Sep 2025, 76.2% in Oct–Dec 2025, 79.7% in Jan–Mar 2026 and 83.6% in Apr–Jun 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 202572 flights79.2%
Oct–Dec 202585 flights76.2%
Jan–Mar 202681 flights79.7%
Apr–Jun 202662 flights83.6%

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

By weekday, UA 1983 did best on Monday at 87.2% on time and worst on Tuesday at 71.4%. Each day rests on about 43 flights, so a gap of 16 points is worth noticing but could still narrow in another year.

Delay causes

Why UA 1983 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 5,292 reported delay minutes.

National Airspace System
34%
Late-arriving aircraft
32%
Carrier
31%
Extreme weather
2%

34% 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 1,804 minutes out of 5,292, against a national NAS share of 21%. The split is drawn from 5,292 delay minutes reported on UA 1983.

Cancellations are rare at 0.33%, below the national 1.81% 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

8.8% 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 an hour and a half, 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. 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 LAX to TPA (49), ORD to LAX (48) and ORD to IAH (32), 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. 300 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 79.4% on time with 0.33% cancelled over 300 flights. Those are rates from the past twelve months, not a forecast for any particular day.

Where to go next

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.

Key figures