Flight number record

UA 623

United Airlines · New York to Chicago

Route: LGA → ORD
Departs: 09:15
Flights: 328
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s UA 623, check with United Airlines.

UA 623 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 about an hour on average. That is a workable record, not a spotless one. That rests on 328 flights, with a median arrival 5 minutes early.

On time

80.0%

Arrivals under 15 minutes late, of 315 completed flights

Avg delay

63 min

Across delayed arrivals only, not all flights

Cancelled

3.66%

National rate is 1.81%

1 hour+ late

5.4%

National rate is 8.1%

These figures cover 328 flights between July 2025 and June 2026. The median arrival is 5 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.

Schedule

When UA 623 flies

UA 623 flies LGA to ORD without a single fixed slot. Its most common scheduled departure was 09:15, used on 135 of 328 flights, with 09:10 (84 flights) and 09:18 (68 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 09:15135 flights41.2%
Departs 09:1084 flights25.6%
Departs 09:1868 flights20.7%

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 09:15 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and UA 623 runs 4 points worse at 80.0%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Against the route

UA 623 next to LGA to ORD

Every carrier on LGA to ORD combined arrived on time 67.3% of the time across 11,625 flights, so UA 623 is 13 points ahead of it. United flew 4,662 flights on the same city pair under all its flight numbers, including this one, and those ran 66.7% on time. Across its whole network United Airlines managed 79.0%, close to this flight's figure.

UA 623 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 623thin sample	328	80.0%	63 min	3.66%	B−
All United Airlines on LGA–ORD	4,662	66.7%	88 min	3.69%	C−
All carriers on LGA–ORD	11,625	67.3%	89 min	4.94%	C−
United Airlines, whole network	821,041	79.0%	72 min	1.01%	B

Across the year

UA 623 quarter by quarter

UA 623 did not run the same all year. Its best quarter was Jul–Sep 2025 at 87.7% on time and its weakest Oct–Dec 2025 at 69.2%, a swing of 19 points on roughly 82 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 202585 flights87.7%
Oct–Dec 202579 flights69.2%
Jan–Mar 202680 flights81.9%
Apr–Jun 202684 flights81.0%

Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, UA 623 ranged from 73.5% on Sunday to 85.1% on Monday. With about 47 flights behind each day, a spread of 12 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why UA 623 runs late

One category carries most of the weight here. National Airspace System accounts for 54% of the 3,983 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

National Airspace System
54%
Carrier
22%
Extreme weather
12%
Late-arriving aircraft
11%

Extreme weather accounts for 12% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the quarterly figures above are the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.0 times the usual weather exposure. The split is drawn from 3,983 delay minutes reported on UA 623.

Cancellations run at 3.66%, against 1.81% nationally. That is roughly one flight in 25 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and routes

What a delay on this flight costs

5.4% 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 about an hour, which a normal layover absorbs.

The 733 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 thirteen other city pairs in the data, including ORD to BZN (41), ORD to ALB (37) and ORD to SEA (32), but none flew often enough under UA 623 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to LGA to ORD only.

One caution: this is a thin sample. 328 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 623

For a booking, the cancellation rate is the figure to plan around on UA 623: 3.66% of its 328 scheduled flights did not operate. A late arrival costs about an hour, but a cancellation costs the day, so leave a later option open.

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