Flight number record

UA 2124

United Airlines · Houston to Chicago

Route: IAH → ORD
Departs: 09:35
Flights: 349
Period: September 2025 to August 2026

Historical statistics for September 2025 to August 2026, not live status. For today’s UA 2124, check with United Airlines.

UA 2124 earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 349 flights, with a median arrival 11 minutes early.

Set against the rest of the country, UA 2124's record is 8 points better than the US average of 77.3%. That gap is worth roughly 75 fewer late arrivals for every thousand flights.

On time

84.8%

Arrivals under 15 minutes late, of 348 completed flights

Avg delay

65 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.89%

1 hour+ late

4.6%

National rate is 8.3%

These figures cover 349 flights between September 2025 and August 2026. The median arrival is 11 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.

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

Schedule

When UA 2124 flies

UA 2124 flies IAH to ORD without a single fixed slot. Its most common scheduled departure was 09:35, used on 101 of 349 flights, with 09:30 (95 flights) next.

Departs 09:35101 flights28.9%
Departs 09:3095 flights27.2%

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 09:35 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and UA 2124 runs level with that at 84.8%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

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 2124 next to IAH to ORD

Every carrier on IAH to ORD combined arrived on time 75.1% of the time across 6,142 flights, so UA 2124 is 10 points ahead of it. United flew 4,084 flights on the same city pair under all its flight numbers, including this one, and those ran 78.2% on time. Across its whole network United Airlines managed 78.8%, which this flight beats by 6 points.

UA 2124 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 2124thin sample	349	84.8%	65 min	0.00%	B+
All United Airlines on IAH–ORD	4,084	78.2%	69 min	0.59%	B+
All carriers on IAH–ORD	6,142	75.1%	83 min	1.50%	B
United Airlines, whole network	830,825	78.8%	73 min	1.02%	B

Across the year

UA 2124 quarter by quarter

Quarter by quarter UA 2124 held fairly steady: 90.0% in Jul–Sep 2025, 88.2% in Oct–Dec 2025, 82.2% in Jan–Mar 2026, 82.4% in Apr–Jun 2026 and 85.2% in Jul–Sep 2026. A spread of 8 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202530 flights90.0%
Oct–Dec 202576 flights88.2%
Jan–Mar 202690 flights82.2%
Apr–Jun 202691 flights82.4%
Jul–Sep 202662 flights85.2%

Scale runs 75% to 95%.

By weekday, UA 2124 did best on Thursday at 92.0% on time and worst on Sunday at 80.0%. Each day rests on about 50 flights, so a gap of 12 points is worth noticing but could still narrow in another year.

Arrival by arrival

How late UA 2124 runs when it is late

UA 2124 often beats the schedule: 131 of 348 completed flights, 38%, arrived 15 minutes or more early. The 53 late arrivals split 25 under half an hour, 12 between 30 and 60 minutes, and 16 an hour or more.

15+ min early131 flights37.6%
Within 15 min164 flights47.1%
15–29 min late25 flights7.2%
30–59 min late12 flights3.4%
1–2 hours late10 flights2.9%
2+ hours late6 flights1.7%

Scale runs 0% to 100%.

Share of 348 completed flights by arrival against schedule.

Time lost at the gate mostly stays lost. Of 37 departures that left 15 minutes late or more, only 4 made it up before arrival. In the other direction, 20 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 2124

The latest arrival of the period was on 29 November 2025, 11 hours 8 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. Three of the five worst days fell in November 2025.

The latest arrivals of UA 2124 in the period
Date	Arrived late by	Largest filed cause
29 November 2025	11 hours 8 minutes	National Airspace System
15 March 2026	2 hours 47 minutes	National Airspace System
10 November 2025	2 hours 45 minutes	National Airspace System
30 November 2025	2 hours 23 minutes	National Airspace System
11 August 2026	2 hours 15 minutes	National Airspace System

Delay causes

Why UA 2124 runs late

National Airspace System accounts for 68% of the 3,451 delay minutes carriers reported here, and the remaining four split what is left.

National Airspace System
68%
Carrier
15%
Late-arriving aircraft
14%
Extreme weather
3%

68% 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 2,338 minutes out of 3,451, against a national NAS share of 21%. The split is drawn from 3,451 delay minutes reported on UA 2124.

Cancellations are rare at 0.00%, below the national 1.89% and low enough to earn the plus on the grade. Almost no flights are called off; the risk here is arriving late, not not arriving.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 4.6% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

The 925 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 nine other city pairs in the data, including MSY to IAH (180), ORD to LAX (83) and ORD to BWI (47), but none flew often enough under UA 2124 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to IAH to ORD only.

One caution: this is a thin sample. 349 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 2124

For a booking, read UA 2124 as 84.8% on time with 0.00% cancelled over 349 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, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures