United Airlines
UA399Chicago to Boston
United Airlines flight UA399 flies from Chicago O'Hare (ORD) to Boston (BOS), 1,391 km. Over August 2025 to May 2026 it usually arrives about 15 minutes late: 67% of 347 flights arrived within 15 minutes of schedule and 1.7% were cancelled (US Department of Transportation data).
On-time record, last 12 months
67%
on time (within 15 min)
24%
more than 30 min late
1.7%
cancelled
+15 min
average arrival vs schedule
Every operation of UA399, August 2025 to May 2026: 347 flights. Source: US Bureau of Transportation Statistics, public domain.
Routes flown as UA399
- Chicago O'Hare (ORD) to Boston (BOS)193 flights
- Newark Liberty (EWR) to New Orleans (MSY)32 flights
- Newark Liberty (EWR) to Fort Lauderdale Hollywood (FLL)24 flights
- Seattle Tacoma (SEA) to Denver (DEN)21 flights
- Dallas-Fort Worth (DFW) to Houston (IAH)21 flights
- Houston (IAH) to San Francisco (SFO)21 flights
- Chicago O'Hare (ORD) to Dallas-Fort Worth (DFW)20 flights
- Boston (BOS) to Newark Liberty (EWR)13 flights
- Houston (IAH) to Charlotte Douglas (CLT)2 flights
Other flights from Chicago to Boston
More about Chicago O'Hare (ORD) and Boston (BOS).
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