Flight number record

DL 318

Delta Air Lines · Boston to Los Angeles

Route: BOS → LAX
Departs: 16:30
Flights: 345
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 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, 5 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 345 flights, with a median arrival 1 minute early.

The national on-time rate over the same period is 77.6%, so DL 318 runs 5 points behind the country as a whole. Across a thousand flights that is about 52 extra late arrivals.

On time

72.4%

Arrivals under 15 minutes late, of 340 completed flights

Avg delay

76 min

Across delayed arrivals only, not all flights

Cancelled

1.45%

National rate is 1.81%

1 hour+ late

7.9%

National rate is 8.1%

These figures cover 345 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.

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 16:40 (53 flights) and 12:45 (47 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 16:3077 flights22.3%
Departs 16:4053 flights15.4%
Departs 12:4547 flights13.6%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

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 72.4%, and DL 318 runs level with that at 72.4%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

DL 318 next to BOS to LAX

Every carrier on BOS to LAX combined arrived on time 74.9% of the time across 4,713 flights, so DL 318 is 3 points behind it. Delta flew 1,228 flights on the same city pair under all its flight numbers, including this one, and those ran 75.2% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 9 points.

DL 318 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 318thin sample	345	72.4%	76 min	1.45%	C
All Delta Air Lines on BOS–LAX	1,228	75.2%	76 min	1.71%	B
All carriers on BOS–LAX	4,713	74.9%	76 min	1.42%	C
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	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 77.2% on time and its weakest Oct–Dec 2025 at 66.7%, a swing of 11 points on roughly 86 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 202592 flights77.2%
Oct–Dec 202592 flights66.7%
Jan–Mar 202672 flights71.0%
Apr–Jun 202689 flights74.2%

Scale runs 60% to 85%. Rows with fewer than 30 flights show a dash.

By weekday, DL 318 did best on Thursday at 78.4% on time and worst on Saturday at 64.9%. Each day rests on about 49 flights, so a gap of 14 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 318 runs late

One category carries most of the weight here. Carrier accounts for 46% of the 7,169 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Carrier
46%
Late-arriving aircraft
31%
National Airspace System
23%

The largest share of delay minutes, 46%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 3,278 of the 7,169 delay minutes reported here. The split is drawn from 7,169 delay minutes reported on DL 318.

Cancellations sit at 1.45% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and routes

What a delay on this flight costs

7.9% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.

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 72.4% on time with 1.45% cancelled over 345 flights. Those are rates from the past twelve months, not a forecast for any particular day.

Where to go next

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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures