Route on-time record

BOS to SFO: most on-time flights and the best time to fly

Boston (Boston Logan International Airport) to San Francisco (San Francisco International Airport). 4,612 nonstop flights in Jun 2025 to May 2026, 75% arrived within 15 minutes and 1.1% were cancelled. The most reliable flight number was JetBlue 1333 at 6:20 AM.

Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.

BOS → SFO

Boston to San Francisco: 4,612 nonstop flights a year

On time (12 months)

75%

Cancelled

1.1%

avg delay 17 min

Best time to leave

Before 9 AM

85% on time vs 61% 6 to 9 PM

Most reliable airline

United

78% chance on time

Check BOS to SFO fares

Fares open on our travel partner (Aviasales). Pick the flight number you chose here.

Most reliable nonstop flights

Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.

#1 · JetBlue 1333
6:20 AM → 10:05 AM6h 45m nonstop
Local times, typical schedule. Last flown 2026-05-31.
88%
chance on time
On time (history)
91%
Cancelled
0.0%
Avg arrival delay
6 min
- Arrived on time 91% of the time (178 flights, Jun 2025 to May 2026).
- Never cancelled in 179 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 85% on time; 6 to 9 PM: 61%).
- Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
Moderate track record · 178 flights
Find JetBlue 1333 fares Opens this date on Aviasales
#2 · JetBlue 1833
9:00 AM → 12:37 PM6h 37m nonstop
Local times, typical schedule. Last flown 2026-05-31.
88%
chance on time
On time (history)
91%
Cancelled
0.0%
Avg arrival delay
5 min
- Arrived on time 91% of the time (158 flights, Jun 2025 to May 2026).
- Never cancelled in 158 scheduled flights.
- Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
- Lands inside SFO's trouble window: 61% of its 333 ground stops and delay programs started between 7 AM and 1 PM.
Moderate track record · 158 flights
Find JetBlue 1833 fares Opens this date on Aviasales
#3 · United 1367
1:52 PM → 5:36 PM6h 44m nonstop
Local times, typical schedule. Last flown 2026-05-20.
84%
chance on time
On time (history)
84%
Cancelled
1.2%
Avg arrival delay
17 min
- Arrived on time 84% of the time (81 flights, Jun 2025 to May 2026).
- Departs inside BOS's trouble window: 79% of its 196 ground stops and delay programs started between noon and 6 PM.
Moderate track record · 81 flights
Find United 1367 fares Opens this date on Aviasales
#4 · United 2441
6:00 AM → 9:11 AM6h 43m nonstop
Local times, typical schedule. Last flown 2026-05-31.
83%
chance on time
On time (history)
84%
Cancelled
1.0%
Avg arrival delay
8 min
- Arrived on time 84% of the time (310 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 85% on time; 6 to 9 PM: 61%).
- Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
- Lands inside SFO's trouble window: 61% of its 333 ground stops and delay programs started between 7 AM and 1 PM.
Strong track record · 310 flights
Find United 2441 fares Opens this date on Aviasales
#5 · United 1074
11:10 AM → 2:54 PM6h 44m nonstop
Local times, typical schedule. Last flown 2026-05-31.
83%
chance on time
On time (history)
84%
Cancelled
0.4%
Avg arrival delay
14 min
- Arrived on time 84% of the time (265 flights, Jun 2025 to May 2026).
- Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
Strong track record · 265 flights
Find United 1074 fares Opens this date on Aviasales
#6 · United 1458
7:55 AM → 11:55 AM7h 00m nonstop
Local times, typical schedule. Last flown 2026-03-28.
83%
chance on time
On time (history)
83%
Cancelled
0.0%
Avg arrival delay
7 min
- Arrived on time 83% of the time (24 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 85% on time; 6 to 9 PM: 61%).
- Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
- Lands inside SFO's trouble window: 61% of its 333 ground stops and delay programs started between 7 AM and 1 PM.
Limited track record · 24 flights
Find United 1458 fares Opens this date on Aviasales
#7 · United 2623
7:35 AM → 11:20 AM6h 45m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as United 2011; its record covers all of them.
82%
chance on time
On time (history)
78%
Cancelled
0.0%
Avg arrival delay
10 min
- Arrived on time 78% of the time (64 flights, Jun 2025 to May 2026).
- Never cancelled in 64 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 85% on time; 6 to 9 PM: 61%).
- Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
Moderate track record · 64 flights
Find United 2623 fares Opens this date on Aviasales
#8 · United 2002
9:07 AM → 12:34 PM6h 27m nonstop
Local times, typical schedule. Last flown 2026-05-31.
82%
chance on time
On time (history)
73%
Cancelled
0.0%
Avg arrival delay
19 min
- Arrived on time 73% of the time (11 flights, Jun 2025 to May 2026).
- Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
- Lands inside SFO's trouble window: 61% of its 333 ground stops and delay programs started between 7 AM and 1 PM.
- 67% of its delay minutes came from the plane arriving late from an earlier flight.
Limited track record · 11 flights
Find United 2002 fares Opens this date on Aviasales
#9 · Delta 977
7:40 AM → 11:38 AM6h 49m nonstop
Local times, typical schedule. Last flown 2026-05-31.
82%
chance on time
On time (history)
83%
Cancelled
3.4%
Avg arrival delay
9 min
- Arrived on time 83% of the time (144 flights, Jun 2025 to May 2026).
- Cancelled 3.4% of the time (5 of 149).
- Leaves in this route's most on-time window (Before 9 AM: 85% on time; 6 to 9 PM: 61%).
- Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
Moderate track record · 144 flights
Find Delta 977 fares Opens this date on Aviasales
#10 · JetBlue 133
7:10 AM → 11:10 AM7h 00m nonstop
Local times, typical schedule. Last flown 2026-04-28.
81%
chance on time
On time (history)
84%
Cancelled
4.9%
Avg arrival delay
8 min
- Arrived on time 84% of the time (176 flights, Jun 2025 to May 2026).
- Cancelled 4.9% of the time (9 of 185).
- Leaves in this route's most on-time window (Before 9 AM: 85% on time; 6 to 9 PM: 61%).
- Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
Moderate track record · 176 flights
Find JetBlue 133 fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

United Airlines78%
1,816 flights · 79% on time as flown · 1.1% cancel
Delta Air Lines73%
882 flights · 74% on time as flown · 1.3% cancel
JetBlue73%
1,619 flights · 74% on time as flown · 1.2% cancel
Alaska Airlines62%
294 flights · 63% on time as flown · 0.6% cancel

On time by departure time

All airlines, scheduled local departure, Jun 2025 to May 2026.

Before 9 AM85%
1,495 flights · avg delay 9 min
9 AM to noon83%
706 flights · avg delay 12 min
Noon to 3 PM82%
357 flights · avg delay 13 min
3 to 6 PM68%
855 flights · avg delay 24 min
6 to 9 PM61%
1,113 flights · avg delay 27 min

Best day: Tuesday (81%). Worst: Sunday (72%).

On time by month

All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.

What delays this route

Late-arriving aircraft38%
Air traffic control and airport volume34%
Airline (crew, maintenance, boarding)25%
Severe weather2%

Share of delay minutes by the cause airlines report to the US DOT.

Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure

BOS to SFO questions

What time of day is best to fly BOS to SFO?: Before 9 AM: 85% of flights arrived on time, against 61% for departures 6 to 9 PM. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
Which airline is most on time from BOS to SFO?: United, with a season-adjusted 78% chance of operating and arriving on time over 1,816 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
What is the worst month for delays on BOS to SFO?: April (71% on time); the best was September (81%), averaged over Jun 2023 to May 2026.
Is this a prediction for my flight?: No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.

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