Flight number record
DL 318
Delta Air Lines · Boston to Los Angeles
- Route
- BOS → LAX
- Departs
- 16:30
- Flights
- 345
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 318, check with Delta Air Lines.
DL 318 sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.3%. The late ones land a little over an hour behind schedule. That rests on 345 flights, with a median arrival right on schedule.
The national on-time rate over the same period is 77.3%, so DL 318 runs 7 points behind the country as a whole. Across a thousand flights that is about 65 extra late arrivals.
Key figures
On time
70.8%
Arrivals under 15 minutes late, of 336 completed flights
Avg delay
74 min
Across delayed arrivals only, not all flights
Cancelled
2.32%
National rate is 1.89%
1 hour+ late
9.8%
National rate is 8.3%
These figures cover 345 flights between September 2025 and August 2026. Beyond the headline rate, 9.8% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When DL 318 flies
DL 318 flies BOS to LAX without a single fixed slot. Its most common scheduled departure was 16:30, used on 77 of 345 flights, with 16:25 (57 flights) and 16:40 (53 flights) next.
- Departs 16:3077 flights22.3%
- Departs 16:2557 flights16.5%
- Departs 16:4053 flights15.4%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 16:30 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 71.9%, and DL 318 runs level with that at 70.8%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
DL 318 next to BOS to LAX
Every carrier on BOS to LAX combined arrived on time 73.7% of the time across 4,794 flights, so DL 318 is 3 points behind it. Delta flew 1,238 flights on the same city pair under all its flight numbers, including this one, and those ran 73.9% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight trails by 10 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 318thin sample | 345 | 70.8% | 74 min | 2.32% | C |
| All Delta Air Lines on BOS–LAX | 1,238 | 73.9% | 74 min | 2.18% | C |
| All carriers on BOS–LAX | 4,794 | 73.7% | 79 min | 1.81% | C |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 318 quarter by quarter
DL 318 did not run the same all year. Its best quarter was Jul–Sep 2025 at 76.7% on time and its weakest Oct–Dec 2025 at 66.7%, a swing of 10 points on roughly 69 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202530 flights76.7%
- Oct–Dec 202592 flights66.7%
- Jan–Mar 202672 flights71.0%
- Apr–Jun 202689 flights74.2%
- Jul–Sep 202662 flights69.0%
Scale runs 60% to 80%.
By weekday, DL 318 did best on Thursday at 82.4% on time and worst on Saturday at 60.0%. Each day rests on about 49 flights, so a gap of 22 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 318 runs when it is late
The 98 late arrivals split 43 under half an hour, 22 between 30 and 60 minutes, and 33 an hour or more.
- 15+ min early81 flights24.1%
- Within 15 min157 flights46.7%
- 15–29 min late43 flights12.8%
- 30–59 min late22 flights6.5%
- 1–2 hours late12 flights3.6%
- 2+ hours late21 flights6.3%
Scale runs 0% to 100%.
Share of 336 completed flights by arrival against schedule.
22 of 84 late departures made up the time and arrived on time, 26% of them. In the other direction, 36 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at LAX.
The worst days
Worst days for DL 318
The latest arrival of the period was on 3 August 2026, 6 hours 19 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 3 August 2026 | 6 hours 19 minutes | Carrier |
| 29 December 2025 | 5 hours 5 minutes | Carrier |
| 27 December 2025 | 4 hours 43 minutes | Carrier |
| 29 August 2026 | 4 hours 37 minutes | Late-arriving aircraft |
| 13 June 2026 | 4 hours 32 minutes | Late-arriving aircraft |
Delay causes
Why DL 318 runs late
Carrier accounts for 44% of the 7,259 delay minutes carriers reported here, and the remaining four split what is left.
- 44%Carrier
- 35%Late-arriving aircraft
- 21%National Airspace System
35% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 7,259 reported delay minutes here, that single category outweighs weather by 35 to one. The split is drawn from 7,259 delay minutes reported on DL 318.
Cancellations sit at 2.32% against a national 1.89%, which is ordinary. Diversions add another 0.29%.
Connections and routes
What a delay on this flight costs
9.8% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
At 2,611 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
Every one of the 345 flights under DL 318 in the data flew BOS to LAX. The number was not reused on any other city pair, which makes this a clean record of one route.
One caution: this is a thin sample. 345 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking DL 318
For a booking, read DL 318 as 70.8% on time with 2.32% cancelled over 345 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- BOS to LAX, every carrier and departure
- LAX to BOS, the return direction
- Delta Air Lines 479 on the same route78.4%
- JetBlue Airways 287 on the same route85.1%
- JetBlue Airways 387 on the same route64.5%
- JetBlue Airways 487 on the same route72.3%
- Delta Air Lines 321 on the same route65.8%
- Boston Logan International (BOS) delay statistics
- Los Angeles International (LAX) delay statistics
- Delta Air Lines on-time record
- Every Delta Air Lines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means Delta Air Lines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.