UA521United Airlines · IAH → BOS
live · 6m ago
Route confirmed United Airlines

UA521 HoustonIAH · 18:35 BostonBOS · 23:39

UA521 by United Airlines flies from Houston (IAH) to Boston (BOS) for the Mon, Oct 19 departure.

Right nowScheduled · gate C37
18:35

departs IAH · on schedule

Typical gate push+3 minmedian posted departure
Typical arrival−8 minmedian over 1 operations
Wins back in air~11 minmedian gate push vs arrival · how planes make up time →

The route today

live boards
IAHHoustonOn-time likelyIAH delay board →
BOSBostonOn-time likelyBOS delay board →
IAH→BOSevery carrier, schedules and on-time historyRoute intelligence →

Weather lens

Delay & cancellation outlook for this flight

Measured, 90-day sample
37%Chance of 15+ min delay
3.2%Chance of cancellation
+9 minAvg hub delay right now

Conditions at IAH and BOS are near their clear-air norm right now, so this reflects the route's recent baseline rather than a weather penalty. For this route and airline, under conditions like today's, over the last 90 days.

Pro Flight Search tracking, 90 days · the weather × delay correlation study → · live weather risk by airport →

When it flies

scheduled departures
061422
M
T
W
T
F
S
S

Each mark is a scheduled departure at its origin-local time. Today is highlighted.

Other Houston to Boston flights today

same route · United Airlines
UA1977departs 07:20
UA1207departs 08:30
UA2393departs 09:35
UA1226departs 12:25
UA2296departs 16:48

If UA521 is cancelled, these are the other United Airlines nonstop flights from Houston to Boston on the same day, with scheduled departure times in IAH local time. Most flights posting a delay still operate — rebooking usually only beats a very large posted delay. Every airline on this route →

How UA521 actually runs

Pro Flight Search has tracked every published board update for UA521 across the IAH and BOS boards: schedule changes, gate pushes and actual clocks. Early read — pattern not clear yet. Only 1 completed leg so far: departed +3 min. Not enough to call it.

The verdict above is that record speaking, so it reflects how UA521 operates rather than what the timetable promises. Numbers refresh as new flights operate.

Technical record

How this operation is measured

board clocks

Board log

scheduled → actual, per operation
10-18IAH 18:35 18:38 (+3)BOS 23:39 23:31 (−8)

Board clocks recorded as IAH and BOS published them.

Planning around UA521? Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure

Cite this data

Journalists, bloggers, and researchers may cite this page with attribution and a link to Pro Flight Search.

Suggested citation

Pro Flight Search — UA521 Houston to Boston on-time performance, measured from the IAH and BOS airport boards.

Canonical URL
https://proflightsearch.com/flight/UA521
How we measure this →