Flight number record

UA 303

United Airlines · Kansas City to Chicago

Route: MCI → ORD
Departs: 08:00
Flights: 364
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s UA 303, check with United Airlines.

UA 303 sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 364 flights, with a median arrival 2 minutes late.

On time

73.8%

Arrivals under 15 minutes late, of 359 completed flights

Avg delay

81 min

Across delayed arrivals only, not all flights

Cancelled

1.37%

National rate is 1.81%

1 hour+ late

9.7%

National rate is 8.1%

These figures cover 364 flights between July 2025 and June 2026. Beyond the headline rate, 9.7% 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 303 flies

UA 303 flies MCI to ORD without a single fixed slot. Its most common scheduled departure was 08:00, used on 69 of 364 flights, with 15:22 (42 flights) and 15:24 (37 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 08:0069 flights19.0%
Departs 15:2242 flights11.5%
Departs 15:2437 flights10.2%

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 08:00 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and UA 303 runs 10 points worse at 73.8%. 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 303 next to MCI to ORD

Every carrier on MCI to ORD combined arrived on time 74.7% of the time across 4,148 flights, so UA 303 is about level with it. United flew 1,434 flights on the same city pair under all its flight numbers, including this one, and those ran 76.5% on time. Across its whole network United Airlines managed 79.0%, which this flight trails by 5 points.

UA 303 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 303thin sample	364	73.8%	81 min	1.37%	C
All United Airlines on MCI–ORD	1,434	76.5%	82 min	2.02%	B
All carriers on MCI–ORD	4,148	74.7%	97 min	2.80%	C
United Airlines, whole network	821,041	79.0%	72 min	1.01%	B

Across the year

UA 303 quarter by quarter

UA 303 did not run the same all year. Its best quarter was Jan–Mar 2026 at 79.5% on time and its weakest Jul–Sep 2025 at 69.2%, a swing of 10 points on roughly 91 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 202591 flights69.2%
Oct–Dec 202592 flights72.5%
Jan–Mar 202690 flights79.5%
Apr–Jun 202691 flights74.2%

Scale runs 60% to 85%. Rows with fewer than 30 flights show a dash.

By weekday, UA 303 did best on Tuesday at 81.1% on time and worst on Friday at 66.0%. Each day rests on about 52 flights, so a gap of 15 points is worth noticing but could still narrow in another year.

Delay causes

Why UA 303 runs late

One category carries most of the weight here. National Airspace System accounts for 45% of the 7,620 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
45%
Late-arriving aircraft
41%
Carrier
9%
Extreme weather
6%

41% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 7,620 reported delay minutes here, that single category outweighs weather by 7 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 7,620 delay minutes reported on UA 303.

Cancellations sit at 1.37% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and routes

What a delay on this flight costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.7% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

The same number turns up on five other city pairs in the data, including ORD to IAH (37), ORD to BWI (35) and ORD to SLC (31), but none flew often enough under UA 303 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to MCI to ORD only.

One caution: this is a thin sample. 364 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 303

For a booking, read UA 303 as 73.8% on time with 1.37% cancelled over 364 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