Flight number record

UA 1550

United Airlines · Denver to San Luis Obispo

Route: DEN → SBP
Departs: 19:25
Flights: 321
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s UA 1550, check with United Airlines.

UA 1550 lands a B+, level with the national rate of 77.6%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by close to two hours on average. That is a workable record, not a spotless one. That rests on 321 flights, with a median arrival 5 minutes early.

On time

78.2%

Arrivals under 15 minutes late, of 312 completed flights

Avg delay

115 min

Across delayed arrivals only, not all flights

Cancelled

0.62%

National rate is 1.81%

1 hour+ late

10.6%

National rate is 8.1%

These figures cover 321 flights between July 2025 and June 2026. Beyond the headline rate, 10.6% 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 1550 flies

UA 1550 flies DEN to SBP without a single fixed slot. Its most common scheduled departure was 19:25, used on 74 of 321 flights, with 19:10 (54 flights) and 19:15 (40 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 19:2574 flights23.1%
Departs 19:1054 flights16.8%
Departs 19:1540 flights12.5%

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 19:25 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and UA 1550 runs 10 points better at 78.2%. 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 1550 next to DEN to SBP

Every carrier on DEN to SBP combined arrived on time 76.8% of the time across 724 flights, so UA 1550 is about level with it. Across its whole network United Airlines managed 79.0%, close to this flight's figure.

UA 1550 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 1550thin sample	321	78.2%	115 min	0.62%	B+
All United Airlines on DEN–SBP	403	76.1%	104 min	0.50%	B+
All carriers on DEN–SBP	724	76.8%	80 min	0.28%	B+
United Airlines, whole network	821,041	79.0%	72 min	1.01%	B

Across the year

UA 1550 quarter by quarter

UA 1550 did not run the same all year. Its best quarter was Oct–Dec 2025 at 87.4% on time and its weakest Jul–Sep 2025 at 62.1%, a swing of 25 points on roughly 80 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 202590 flights62.1%
Oct–Dec 202591 flights87.4%
Jan–Mar 202690 flights85.4%
Apr–Jun 202650 flights77.6%

Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, UA 1550 did best on Wednesday at 88.9% on time and worst on Sunday at 62.2%. Each day rests on about 46 flights, so a gap of 27 points is worth noticing but could still narrow in another year.

Delay causes

Why UA 1550 runs late

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 7,846 reported delay minutes.

Late-arriving aircraft
41%
Extreme weather
25%
National Airspace System
19%
Carrier
14%

Extreme weather accounts for 25% 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 4.0 times the usual weather exposure. The split is drawn from 7,846 delay minutes reported on UA 1550.

Cancellations are rare at 0.62%, 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

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.6% 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 931 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 four other city pairs in the data, including ORD to BWI (35), DTW to DEN (31) and DTW to SFO (4), but none flew often enough under UA 1550 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DEN to SBP only.

One caution: this is a thin sample. 321 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 1550

For a booking, read UA 1550 as 78.2% on time with 0.62% cancelled over 321 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