Route profile
SAN→BOS
Flight reliability, delays and best times to fly from San Diego to Boston, 2,588 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 36% of comparable major US routes (4,598 compared)
Calculated from 5,087 flights. How this is calculated
SAN → BOS arrives on time 75.5% of the time; the return trip, BOS → SAN, arrives on time 76.4% of the time.
SAN → BOS spends 33.9 minutes on the ground on a 2,588-mile trip: 23.0 minutes from pushback to wheels-up at SAN and 10.9 minutes from touchdown to gate at BOS.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What sets this route apart
Where SAN to BOS differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
SAN to BOS struggles most at 2 PM: 57.0% of its flights scheduled then arrive on time, 17.6 points behind the 74.6% on routes of similar length at the same hour. Against all other routes the gap is 17.6 points.
SAN to BOS is at its best against routes of similar length for flights scheduled at 9 PM: 86.5% arrive on time, 7.6 points ahead of the 78.9% those routes manage at that hour. Against all other routes the gap is 17.1 points.
Thursday is the day SAN to BOS slips furthest against routes of similar length, 70.3% on time where they average 77.0%, 6.7 points lower. Against all other routes the gap is 6.5 points.
In September, SAN to BOS runs 10.6 points below routes of similar length, 71.0% on time to 81.6%. Against all other routes the gap is 11.4 points.
May is kinder to SAN to BOS than to routes of similar length: 83.5% on time against 77.9%, 5.6 points better. Against all other routes the gap is 8.3 points.
SAN to BOS against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 2 PM departures | 57.0% | routes of similar length | 74.6% | −17.6 pts | 158 here, 25,554 there |
| Hour: 9 PM departures | 86.5% | routes of similar length | 78.9% | +7.6 pts | 651 here, 48,883 there |
| Weekday: Thursday | 70.3% | routes of similar length | 77.0% | −6.7 pts | 738 here, 123,445 there |
| Month: September | 71.0% | routes of similar length | 81.6% | −10.6 pts | 365 here, 68,233 there |
| Month: May | 83.5% | routes of similar length | 77.9% | +5.6 pts | 485 here, 73,932 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 2,588 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
When it goes wrong
July 2023 – July 2026
53 min late
against a median of 6 min early
Percentiles over 5,087 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at BOS after arriving from SAN.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 40% | Likely to miss |
| 45 min | 24% | High risk |
| 60 min | 16% | High risk |
| 90 min | 8.6% | Some risk |
| 120 min | 5.1% | Some risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 0.86% of the time and diverts 0.71% of the time, which a late arrival never shows up in.
Chance of missing is the share of 5,007 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 53 minutes late (90th-percentile gate arrival delay), over 5,087 operations.
Any other layover length: connection checker.
Best time to fly
SAN → BOS flights departing 9 PM–5 AM arrived on time 83.0% of the time, against 66.7% for 12–3 PM departures, a gap of 16.3 percentage points.
By departure window
By departure hour
- 12 AM to 7 AM: too few flights to score
- 8 AM: 74.4% on time from 535 flights
- 9 AM: 73.2% on time from 358 flights
- 10 AM: 71.0% on time from 339 flights
- 11 AM: 64.6% on time from 511 flights
- 12 PM: 73.5% on time from 162 flights
- 1 PM: 67.9% on time from 351 flights
- 2 PM: 57.0% on time from 159 flights
- 3 PM to 7 PM: too few flights to score
- 8 PM: 77.3% on time from 985 flights
- 9 PM: 86.5% on time from 656 flights
- 10 PM: 80.2% on time from 832 flights
- 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why SAN → BOS runs late
July 2023 – July 2026
airspace and airport capacity, including weather-driven flow control
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for SAN → BOS. Only delays of 15 minutes or more are attributed.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| JetBlue | 2,514 | 73.1% | 0.91% | -7 min | 11.1% |
| Alaska Airlines | 1,391 | 76.2% | 0.72% | -3 min | 8.8% |
| Delta Air Lines | 1,124 | 82.3% | 0.98% | -7 min | 2.7% |
JetBlue flew 50.0% of the 5,029 flights listed.
Delta Air Lines arrived on time 9.2 percentage points more often than JetBlue on this route.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
B62120 (8:10 PM) arrived on time 78.8% of the time, 9.1 points more often than B6620 (10:20 AM) at 69.7%.
Weekly and seasonal patterns
By day of week
Saturday is historically the most reliable day and Thursday the least, a gap of 8.9 percentage points.
By month
- Jan: 82.6%
- Feb: 76.6%
- Mar: 75.9%
- Apr: 82.4%
- May: 83.5%
- Jun: 76.2%
- Jul: 67.1%
- Aug: 75.6%
- Sep: 71.0%
- Oct: 74.0%
- Nov: 77.6%
- Dec: 68.3%
July is historically the weakest month and May the strongest, a spread of 16.4 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: too few flights to score (119)
- August 2023: 75.6% from 123 flights
- September 2023: 66.7% from 120 flights
- October 2023: 72.3% from 147 flights
- November 2023: 68.5% from 126 flights
- December 2023: too few flights to score (116)
- January 2024: too few flights to score (88)
- February 2024: too few flights to score (95)
- March 2024: too few flights to score (117)
- April 2024: too few flights to score (116)
- May 2024: 82.8% from 158 flights
- June 2024: 71.8% from 149 flights
- July 2024: 62.7% from 155 flights
- August 2024: 64.8% from 142 flights
- September 2024: too few flights to score (116)
- October 2024: 73.6% from 140 flights
- November 2024: too few flights to score (112)
- December 2024: 63.0% from 122 flights
- January 2025: too few flights to score (117)
- February 2025: too few flights to score (104)
- March 2025: 72.0% from 121 flights
- April 2025: too few flights to score (117)
- May 2025: 77.6% from 165 flights
- June 2025: 77.8% from 172 flights
- July 2025: 70.6% from 181 flights
- August 2025: 84.5% from 175 flights
- September 2025: 72.7% from 135 flights
- October 2025: 75.8% from 163 flights
- November 2025: 78.5% from 137 flights
- December 2025: 76.0% from 134 flights
- January 2026: too few flights to score (119)
- February 2026: too few flights to score (112)
- March 2026: 72.8% from 151 flights
- April 2026: 76.9% from 144 flights
- May 2026: 90.2% from 164 flights
- June 2026: 78.2% from 203 flights
- July 2026: 64.2% from 212 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 77.0% against 75.2% in the 12 months before — improving by 1.8 percentage points.
Data and methodology
Calculated by FlyerIntel from 5,087 SAN → BOS flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed