ON TIMEBOARD

DL 657 on time

Delta Air Lines 657: Salt Lake City to Boston at 9:35 a.m. (past 12 months)

On time
80%
365 flights · likely 76–84%
Cancelled
1.1%
of scheduled flights
Typical arrival
−6 min
median vs schedule
When late
+54 min
average delay
Similar flights
80%
DL, same route & hour

About 1 in 5 DL 657 flights from Salt Lake City arrived 15+ minutes late, diverted or cancelled over the past year (20%); 1.1% were cancelled. The typical flight landed 6 minutes early.

DL 657: SLC → BOS

Scheduled to leave Salt Lake City at 9:35 a.m. local time. Over the past year it arrived on time 80% of the time (365 flights), in line with other DL flights on the route at that hour (80%). Last seen in the data Aug 31, 2026.

Month by month

40%70%100%Sep 2025: 60% on time (30 flights)60SepOct 2025: 58% on time (31 flights)58OctNov 2025: 90% on time (30 flights)90NovDec 2025: 77% on time (31 flights)77DecJan 2026: 77% on time (31 flights)77JanFeb 2026: 89% on time (28 flights)89FebMar 2026: 87% on time (31 flights)87MarApr 2026: 77% on time (30 flights)77AprMay 2026: 94% on time (31 flights)94MayJun 2026: 80% on time (30 flights)80JunJul 2026: 87% on time (31 flights)87JulAug 2026: 87% on time (31 flights)87Aug

By day of week

DayFlightsOn time
Monday5377%
Tuesday5279%
Wednesday5285%
Thursday5283%
Friday5279%
Saturday5279%
Sunday5281%

Why it was late

Air traffic & airport (NAS) 66%Airline (crew, maintenance, ops) 26%Late inbound plane 7%Severe weather 1%

All flights SLC → BOS · Connecting off DL 657? Check the risk

Questions

How often is DL 657 from SLC to BOS late?

Delta Air Lines 657 from Salt Lake City, UT to Boston, MA arrived 15 or more minutes late, was diverted or was cancelled on 20% of 365 scheduled flights between September 2025 and August 2026. 1.1% were cancelled.

Flight numbers change. Figures cover flights with this airline, number and route only. "Likely range" is the 95% interval for the true on-time rate given the number of flights. This is history, not live status: check Delta Air Lines for today's flight. Method.