Flight profile · United Airlines

UA2400

Boston (BOS) to San Francisco (SFO) · scheduled 6:18 PM – 9:50 PM

FlyerIntel does not track flights in the air. This page describes how UA2400 has historically performed, which is a different and more useful question when you are deciding what to book. For today’s status, check with United Airlines.

How UA2400 performs

1,006 operations, 2023-07-01 to 2026-06-30.

On-time arrivals
62.9%
618 of 983 completed
Cancellation rate
1.99%
20 cancelled
Median arrival delay
3 min
Average 19.6 min
Severe delays
15.8%
Arrived 60+ minutes late
Delay when late
71 min
Average, when 15+ min late
Departure punctuality
61.7%
Left the gate on time

UA2400 arrived on time 62.9% of the time, against 75.0% for all BOSSFO flights — this specific departure is 12.1 percentage points worse than the route as a whole. Against United Airlines’s own flights on this route it is 16.2 points worse.

Source: US DOT Bureau of Transportation Statistics · 1,006 operations between 2023-07-01 to 2026-06-30

Against the rest of the route

On timeCancelledMedian delaySevereFlights
UA240062.9%1.99%3 min15.8%1,006
United Airlines on BOSSFO79.1%1.18%-8 min7.6%5,334
All BOSSFO flights75.0%0.96%-6 min8.6%13,723

Source: FlyerIntel analysis of US DOT BTS data · 2023-07-01 to 2026-06-30

By day of week

Does UA2400 run worse on particular days?

Monday58.7%
Tuesday68.3%
Wednesday67.9%
Thursday54.7%
Friday59.4%
Saturday71.3%
Sunday59.4%

Saturday is historically the most reliable day and Thursday the least, a gap of 16.7 percentage points.

Source: FlyerIntel analysis of US DOT BTS data · 2023-07-01 to 2026-06-30 · Days with fewer than 120 operations are not scored.

Other routes UA2400 has flown

A flight number is a slot in a schedule, and carriers reassign it. These are the other city pairs this number served in the analysis period.

RouteOperatedFlightsOn time
SFOLAS San Francisco to Las Vegas2026-01-062026-05-2012979.8%
IAHBOS Houston to Boston2026-04-302026-05-2021
IAHBNA Houston to Nashville2025-10-312025-10-311
SFOSEA San Francisco to Seattle2025-06-262025-07-3135
SFOSBA San Francisco to Santa Barbara2025-05-012025-05-1811
DENSTL Denver to St. Louis2025-03-062025-03-2924
SFOEUG San Francisco to Eugene2023-10-012023-10-2826
SFOONT San Francisco to Ontario2023-09-292023-09-302

Because the same number has served different journeys, the statistics above describe only the route UA2400 currently operates. Blending them would produce an average of two different flights.

Data and methodology

Calculated by FlyerIntel from 1,006 records of UA2400 operating BOSSFO, published by the US DOT Bureau of Transportation Statistics. A flight counts as delayed when it arrives 15 or more minutes after schedule. Cancelled and diverted flights are excluded from the on-time rate and reported separately. Flight numbers are resolved as carrier plus number plus route, because the same number serves different routes over time.

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