Flight number record

UA 1870

United Airlines · San Francisco to Washington

Route: SFO → IAD
Departs: 22:45
Flights: 303
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s UA 1870, check with United Airlines.

UA 1870 earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.6%. When something does go wrong the average delay runs about 45 minutes. That rests on 303 flights, with a median arrival 10 minutes early.

Set against the rest of the country, UA 1870's record is 7 points better than the US average of 77.6%. That gap is worth roughly 74 fewer late arrivals for every thousand flights.

On time

85.0%

Arrivals under 15 minutes late, of 300 completed flights

Avg delay

45 min

Across delayed arrivals only, not all flights

Cancelled

0.99%

National rate is 1.81%

1 hour+ late

3.3%

National rate is 8.1%

These figures cover 303 flights between July 2025 and June 2026. The median arrival is 10 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 1870 flies

UA 1870 flies SFO to IAD without a single fixed slot. Its most common scheduled departure was 22:45, used on 126 of 303 flights, with 22:35 (53 flights) and 23:05 (48 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 22:45126 flights41.6%
Departs 22:3553 flights17.5%
Departs 23:0548 flights15.8%

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 22:45 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.5%, and UA 1870 runs 15 points better at 85.0%. 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 1870 next to SFO to IAD

Every carrier on SFO to IAD combined arrived on time 82.5% of the time across 2,788 flights, so UA 1870 is 3 points ahead of it. United flew 2,690 flights on the same city pair under all its flight numbers, including this one, and those ran 83.8% on time. Across its whole network United Airlines managed 79.0%, which this flight beats by 6 points.

UA 1870 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
UA 1870thin sample	303	85.0%	45 min	0.99%	A+
All United Airlines on SFO–IAD	2,690	83.8%	64 min	0.74%	B+
All carriers on SFO–IAD	2,788	82.5%	64 min	0.75%	B+
United Airlines, whole network	821,041	79.0%	72 min	1.01%	B

Across the year

UA 1870 quarter by quarter

UA 1870 did not run the same all year. Its best quarter was Jan–Mar 2026 at 95.2% on time and its weakest Jul–Sep 2025 at 70.3%, a swing of 25 points on roughly 76 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 flights70.3%
Oct–Dec 202576 flights89.5%
Jan–Mar 202685 flights95.2%
Apr–Jun 202650 flights88.0%

Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, UA 1870 did best on Tuesday at 97.8% on time and worst on Saturday at 76.7%. Each day rests on about 43 flights, so a gap of 21 points is worth noticing but could still narrow in another year.

Delay causes

Why UA 1870 runs late

One category carries most of the weight here. Late-arriving aircraft accounts for 43% of the 2,008 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.

Late-arriving aircraft
43%
Carrier
43%
National Airspace System
14%

43% 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 2,008 reported delay minutes here, that single category outweighs weather by 43 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 2,008 delay minutes reported on UA 1870.

Cancellations sit at 0.99% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 3.3% 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 2,418 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 five other city pairs in the data, including EUG to SFO (52), PSP to SFO (50) and SNA to SFO (48), but none flew often enough under UA 1870 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SFO to IAD only.

One caution: this is a thin sample. 303 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 1870

For a booking, UA 1870 has one of the better records a US domestic flight can show: 85.0% on time and 0.99% cancelled. That is a base rate, not a promise about any single 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