Flight number record

UA 427

United Airlines · San Diego to Newark

Route: SAN → EWR
Departs: 22:30
Flights: 363
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s UA 427, check with United Airlines.

UA 427 lands a B, 6 points better than the national rate of 77.6%. About one flight in six 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 363 flights, with a median arrival 11 minutes early.

Set against the rest of the country, UA 427's record is 6 points better than the US average of 77.6%. That gap is worth roughly 60 fewer late arrivals for every thousand flights.

On time

83.6%

Arrivals under 15 minutes late, of 354 completed flights

Avg delay

63 min

Across delayed arrivals only, not all flights

Cancelled

1.93%

National rate is 1.81%

1 hour+ late

4.8%

National rate is 8.1%

These figures cover 363 flights between July 2025 and June 2026. The median arrival is 11 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 427 flies

UA 427 flies SAN to EWR without a single fixed slot. Its most common scheduled departure was 22:30, used on 53 of 363 flights, with 21:40 (48 flights) and 13:35 (37 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 22:3053 flights14.6%
Departs 21:4048 flights13.2%
Departs 13:3537 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 22:30 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.5%, and UA 427 runs 13 points better at 83.6%. 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 427 next to SAN to EWR

Every carrier on SAN to EWR combined arrived on time 82.9% of the time across 1,561 flights, so UA 427 is about level with it. United flew 1,233 flights on the same city pair under all its flight numbers, including this one, and those ran 82.9% on time. Across its whole network United Airlines managed 79.0%, which this flight beats by 5 points.

UA 427 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 427thin sample	363	83.6%	63 min	1.93%	B
All United Airlines on SAN–EWR	1,233	82.9%	82 min	1.87%	B
All carriers on SAN–EWR	1,561	82.9%	83 min	2.24%	B
United Airlines, whole network	821,041	79.0%	72 min	1.01%	B

Across the year

UA 427 quarter by quarter

UA 427 did not run the same all year. Its best quarter was Apr–Jun 2026 at 93.4% on time and its weakest Jan–Mar 2026 at 76.2%, a swing of 17 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 flights84.3%
Oct–Dec 202592 flights80.0%
Jan–Mar 202689 flights76.2%
Apr–Jun 202691 flights93.4%

Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, UA 427 ranged from 78.4% on Wednesday to 88.0% on Friday. With about 52 flights behind each day, a spread of 10 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why UA 427 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 3,628 reported delay minutes.

National Airspace System
32%
Late-arriving aircraft
26%
Carrier
21%
Extreme weather
20%

Extreme weather accounts for 20% 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 3.3 times the usual weather exposure. The split is drawn from 3,628 delay minutes reported on UA 427.

Cancellations sit at 1.93% against a national 1.81%, which is ordinary. Diversions add another 0.55%.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 4.8% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

At 2,425 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

The same number turns up on one other city pair in the data, including MCO to IAD (1), but none flew often enough under UA 427 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SAN to EWR only.

One caution: this is a thin sample. 363 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 427

For a booking, read UA 427 as 83.6% on time with 1.93% cancelled over 363 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