Flight number record
UA 663
United Airlines · Denver to Medford
- Route
- DEN → MFR
- Departs
- 19:20
- Flights
- 340
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s UA 663, check with United Airlines.
UA 663 lands a B+, about a point worse than the national rate of 77.6%. About one flight in four 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 340 flights, with a median arrival 3 minutes early.
Key figures
On time
76.3%
Arrivals under 15 minutes late, of 338 completed flights
Avg delay
62 min
Across delayed arrivals only, not all flights
Cancelled
0.29%
National rate is 1.81%
1 hour+ late
7.7%
National rate is 8.1%
These figures cover 340 flights between July 2025 and June 2026. The median arrival is 3 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 663 flies
UA 663 flies DEN to MFR without a single fixed slot. Its most common scheduled departure was 19:20, used on 84 of 340 flights, with 19:43 (49 flights) and 19:10 (37 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 19:2084 flights24.7%
- Departs 19:4349 flights14.4%
- Departs 19:1037 flights10.9%
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 19:20 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and UA 663 runs 8 points better at 76.3%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
Against the route
UA 663 next to DEN to MFR
Every carrier on DEN to MFR combined arrived on time 75.8% of the time across 731 flights, so UA 663 is about level with it. United flew 575 flights on the same city pair under all its flight numbers, including this one, and those ran 75.2% on time. Across its whole network United Airlines managed 79.0%, which this flight trails by 3 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 663thin sample | 340 | 76.3% | 62 min | 0.29% | B+ |
| All United Airlines on DEN–MFR | 575 | 75.2% | 52 min | 0.17% | B+ |
| All carriers on DEN–MFR | 731 | 75.8% | 53 min | 0.14% | B+ |
| United Airlines, whole network | 821,041 | 79.0% | 72 min | 1.01% | B |
Across the year
UA 663 quarter by quarter
UA 663 did not run the same all year. Its best quarter was Jan–Mar 2026 at 89.2% on time and its weakest Jul–Sep 2025 at 61.5%, a swing of 28 points on roughly 85 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 202592 flights61.5%
- Oct–Dec 202591 flights85.7%
- Jan–Mar 202666 flights89.2%
- Apr–Jun 202691 flights72.5%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
By weekday, UA 663 did best on Monday at 81.6% on time and worst on Thursday at 67.4%. Each day rests on about 49 flights, so a gap of 14 points is worth noticing but could still narrow in another year.
Delay causes
Why UA 663 runs late
One category carries most of the weight here. Late-arriving aircraft accounts for 71% of the 4,993 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.
- 71%Late-arriving aircraft
- 19%Carrier
- 8%National Airspace System
- 2%Extreme weather
71% 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 4,993 reported delay minutes here, that single category outweighs weather by 46 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 4,993 delay minutes reported on UA 663.
Cancellations are rare at 0.29%, 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
7.7% 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 964 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 six other city pairs in the data, including TPA to DEN (36), SAV to DEN (31) and SJC to DEN (30), but none flew often enough under UA 663 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DEN to MFR only.
One caution: this is a thin sample. 340 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 663
For a booking, read UA 663 as 76.3% on time with 0.29% cancelled over 340 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- DEN to MFR, every carrier and departure
- MFR to DEN, the return direction
- Denver International (DEN) 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
- Why the first flight of the morning is statistically safest
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.