Flight number record
UA 661
United Airlines · Newark to Chicago
- Route
- EWR → ORD
- Departs
- 16:45
- Flights
- 298
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s UA 661, check with United Airlines.
UA 661 earns an F, which is as low as this site's scale goes for a reason. Only 50.2% of flights arrive inside the 15-minute window, 27 points worse than the national rate of 77.6%. Late arrivals average a little over an hour. Treat any tight connection here as a coin flip. That rests on 298 flights, with a median arrival 14 minutes late.
The national on-time rate over the same period is 77.6%, so UA 661 runs 27 points behind the country as a whole. Across a thousand flights that is about 274 extra late arrivals.
Key figures
On time
50.2%
Arrivals under 15 minutes late, of 291 completed flights
Avg delay
73 min
Across delayed arrivals only, not all flights
Cancelled
2.01%
National rate is 1.81%
1 hour+ late
16.8%
National rate is 8.1%
These figures cover 298 flights between July 2025 and June 2026. Beyond the headline rate, 16.8% 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 661 flies
UA 661 flies EWR to ORD without a single fixed slot. Its most common scheduled departure was 16:45, used on 109 of 298 flights, with 16:50 (50 flights) and 16:49 (46 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 16:45109 flights36.6%
- Departs 16:5050 flights16.8%
- Departs 16:4946 flights15.4%
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 16:45 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 72.4%, and UA 661 runs 22 points worse at 50.2%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
Against the route
UA 661 next to EWR to ORD
Every carrier on EWR to ORD combined arrived on time 71.5% of the time across 6,039 flights, so UA 661 is 21 points behind it. United flew 4,389 flights on the same city pair under all its flight numbers, including this one, and those ran 71.1% on time. Across its whole network United Airlines managed 79.0%, which this flight trails by 29 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 661thin sample | 298 | 50.2% | 73 min | 2.01% | F |
| All United Airlines on EWR–ORD | 4,389 | 71.1% | 76 min | 2.26% | C |
| All carriers on EWR–ORD | 6,039 | 71.5% | 81 min | 3.33% | C− |
| United Airlines, whole network | 821,041 | 79.0% | 72 min | 1.01% | B |
Across the year
UA 661 quarter by quarter
UA 661 did not run the same all year. Its best quarter was Jul–Sep 2025 at 60.5% on time and its weakest Jan–Mar 2026 at 43.7%, a swing of 17 points on roughly 75 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 202543 flights60.5%
- Oct–Dec 202575 flights48.6%
- Jan–Mar 202690 flights43.7%
- Apr–Jun 202690 flights52.9%
Scale runs 35% to 65%. Rows with fewer than 30 flights show a dash.
By weekday, UA 661 did best on Tuesday at 58.1% on time and worst on Monday at 36.6%. Each day rests on about 43 flights, so a gap of 22 points is worth noticing but could still narrow in another year.
Delay causes
Why UA 661 runs late
One category carries most of the weight here. National Airspace System accounts for 52% of the 11,000 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.
- 52%National Airspace System
- 24%Late-arriving aircraft
- 23%Carrier
- 1%Extreme weather
52% 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 5,542 minutes out of 11,000, against a national NAS share of 21%. The split is drawn from 10,594 delay minutes reported on UA 661.
Cancellations sit at 2.01% against a national 1.81%, which is ordinary. Diversions add another 0.34%.
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. 16.8% 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 719 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 ten other city pairs in the data, including ORD to LAX (171), SNA to EWR (122) and ORD to DSM (37), but none flew often enough under UA 661 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to EWR to ORD only.
One caution: this is a thin sample. 298 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 661
For a booking, UA 661 is a flight to put a long connection behind. 16.8% of its completed flights arrived an hour or more late, which a short layover will not absorb. If the onward flight is on a separate ticket, the risk sits with you.
Related
Where to go next
- EWR to ORD, every carrier and departure
- ORD to EWR, the return direction
- United Airlines 1525 on the same route79.8%
- United Airlines 1875 on the same route77.4%
- United Airlines 546 on the same route70.4%
- United Airlines 254 on the same route40.1%
- United Airlines 2164 on the same route85.4%
- Newark Liberty International (EWR) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- United Airlines on-time record
- Every United Airlines flight number with a record
- The most and least reliable flight numbers in the US
- The best time of day to fly, according to 7.04 million flight records
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.