Route on-time record
SFO to BOS: most on-time flights and the best time to fly
San Francisco (San Francisco International Airport) to Boston (Boston Logan International Airport). 4,610 nonstop flights in Jun 2025 to May 2026, 78% arrived within 15 minutes and 1.3% were cancelled. The most reliable flight number was United 1015 at 7:00 AM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
SFO → BOS
San Francisco to Boston: 4,610 nonstop flights a year
On time (12 months)
78%
Cancelled
1.3%
avg delay 17 min
Best time to leave
6 to 9 PM
85% on time vs 65% 9 AM to noon
Most reliable airline
United
78% chance on time
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 · United 1015
7:00 AM → 3:54 PM5h 54m nonstop
Local times, typical schedule. Last flown 2026-05-31.
89%
chance on time
- On time (history)
- 93%
- Cancelled
- 0.0%
- Avg arrival delay
- 6 min
- Arrived on time 93% of the time (29 flights, Jun 2025 to May 2026).
- Departs inside SFO's trouble window: 61% of its 333 ground stops and delay programs started between 7 AM and 1 PM.
- Lands inside BOS's trouble window: 79% of its 196 ground stops and delay programs started between noon and 6 PM.
- Short track record (29 flights), so its score leans on the airline's record at this hour.
Limited track record · 29 flights
Find United 1015 fares Opens this date on Aviasales#2 · Delta 400
7:05 AM → 4:01 PM5h 35m nonstop
Local times, typical schedule. Last flown 2026-05-31.
88%
chance on time
- On time (history)
- 90%
- Cancelled
- 1.4%
- Avg arrival delay
- 11 min
- Arrived on time 90% of the time (358 flights, Jun 2025 to May 2026).
- Departs inside SFO's trouble window: 61% of its 333 ground stops and delay programs started between 7 AM and 1 PM.
- Lands inside BOS's trouble window: 79% of its 196 ground stops and delay programs started between noon and 6 PM.
Strong track record · 358 flights
Find Delta 400 fares Opens this date on Aviasales#3 · United 2001
4:15 PM → 1:10 AM5h 55m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as United 1702; its record covers all of them.
86%
chance on time
- On time (history)
- 87%
- Cancelled
- 0.0%
- Avg arrival delay
- 11 min
- Arrived on time 87% of the time (97 flights, Jun 2025 to May 2026).
- Never cancelled in 97 scheduled flights.
- Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).
Moderate track record · 97 flights
Find United 2001 fares Opens this date on Aviasales#4 · United 796
9:16 PM → 6:21 AM6h 02m nonstop
Local times, typical schedule. Last flown 2026-05-31.
85%
chance on time
- On time (history)
- 87%
- Cancelled
- 0.5%
- Avg arrival delay
- 8 min
- Arrived on time 87% of the time (183 flights, Jun 2025 to May 2026).
- Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).
Moderate track record · 183 flights
Find United 796 fares Opens this date on Aviasales#5 · JetBlue 434
7:00 AM → 4:59 PM5h 39m nonstop
Local times, typical schedule. Last flown 2026-05-31.
84%
chance on time
- On time (history)
- 85%
- Cancelled
- 1.3%
- Avg arrival delay
- 12 min
- Arrived on time 85% of the time (315 flights, Jun 2025 to May 2026).
- Departs inside SFO's trouble window: 61% of its 333 ground stops and delay programs started between 7 AM and 1 PM.
- Lands inside BOS's trouble window: 79% of its 196 ground stops and delay programs started between noon and 6 PM.
Strong track record · 315 flights
Find JetBlue 434 fares Opens this date on Aviasales#6 · United 1665
11:20 PM → 8:24 AM6h 03m nonstop
Local times, typical schedule. Last flown 2026-05-31.
83%
chance on time
- On time (history)
- 85%
- Cancelled
- 1.2%
- Avg arrival delay
- 8 min
- Arrived on time 85% of the time (339 flights, Jun 2025 to May 2026).
- Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).
Strong track record · 339 flights
Find United 1665 fares Opens this date on Aviasales#7 · United 2647
8:15 AM → 5:13 PM5h 57m nonstop
Local times, typical schedule. Last flown 2026-05-31.
80%
chance on time
- On time (history)
- 81%
- Cancelled
- 0.6%
- Avg arrival delay
- 17 min
- Arrived on time 81% of the time (340 flights, Jun 2025 to May 2026).
- Departs inside SFO's trouble window: 61% of its 333 ground stops and delay programs started between 7 AM and 1 PM.
- Lands inside BOS's trouble window: 79% of its 196 ground stops and delay programs started between noon and 6 PM.
Strong track record · 340 flights
Find United 2647 fares Opens this date on Aviasales#8 · JetBlue 734
8:44 PM → 5:15 AM5h 42m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as JetBlue 1034; its record covers all of them.
79%
chance on time
- On time (history)
- 80%
- Cancelled
- 2.2%
- Avg arrival delay
- 18 min
- Arrived on time 80% of the time (356 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (6 to 9 PM: 85% on time; 9 AM to noon: 65%).
- Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).
- 58% of its delay minutes came from the plane arriving late from an earlier flight.
Strong track record · 356 flights
Find JetBlue 734 fares Opens this date on Aviasales#9 · JetBlue 934
10:00 PM → 6:40 AM5h 40m nonstop
Local times, typical schedule. Last flown 2026-04-28.
79%
chance on time
- On time (history)
- 78%
- Cancelled
- 0.0%
- Avg arrival delay
- 11 min
- Arrived on time 78% of the time (40 flights, Jun 2025 to May 2026).
- Never cancelled in 40 scheduled flights.
- Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).
- Short track record (40 flights), so its score leans on the airline's record at this hour.
Limited track record · 40 flights
Find JetBlue 934 fares Opens this date on Aviasales#10 · United 1372
12:30 PM → 9:28 PM5h 57m nonstop
Local times, typical schedule. Last flown 2026-05-31.
77%
chance on time
- On time (history)
- 79%
- Cancelled
- 1.3%
- Avg arrival delay
- 16 min
- Arrived on time 79% of the time (299 flights, Jun 2025 to May 2026).
- Departs inside SFO's trouble window: 61% of its 333 ground stops and delay programs started between 7 AM and 1 PM.
Strong track record · 299 flights
Find United 1372 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- United Airlines78%
1,815 flights · 79% on time as flown · 1.0% cancel
- Delta Air Lines77%
883 flights · 78% on time as flown · 1.3% cancel
- JetBlue77%
1,617 flights · 78% on time as flown · 1.7% cancel
- Alaska Airlines76%
294 flights · 77% on time as flown · 0.7% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM85%
1,427 flights · avg delay 13 min
- 9 AM to noon65%
613 flights · avg delay 28 min
- Noon to 3 PM73%
835 flights · avg delay 19 min
- 3 to 6 PM82%
515 flights · avg delay 16 min
- 6 to 9 PM85%
176 flights · avg delay 22 min
- After 9 PM78%
1,044 flights · avg delay 14 min
Best day: Tuesday (83%). Worst: Thursday (74%).
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
- Air traffic control and airport volume39%
- Late-arriving aircraft36%
- Airline (crew, maintenance, boarding)22%
- Severe weather3%
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
SFO to BOS questions
- What time of day is best to fly SFO to BOS?
- 6 to 9 PM: 85% of flights arrived on time, against 65% for departures 9 AM to noon.
- Which airline is most on time from SFO to BOS?
- United, with a season-adjusted 78% chance of operating and arriving on time over 1,815 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 SFO to BOS?
- June (73% on time); the best was November (83%), 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.
More routes from SFO
- BOS to SFO (return)
- SFO to LAX 76%
- SFO to SEA 74%
- SFO to JFK 80%
- SFO to SAN 68%
- SFO to LAS 76%
- SFO to ORD 77%
- SFO to DEN 76%
- SFO to SNA 81%
- SFO to PHX 76%
- SFO to EWR 76%
- SFO to DFW 75%
- SFO to IAH 85%
Live status: FAA delays and ground stops