Flight number record

DL 1031

Delta Air Lines · Atlanta to Detroit

Route: ATL → DTW
Departs: 13:00
Flights: 365
Period: September 2025 to August 2026

Historical statistics for September 2025 to August 2026, not live status. For today’s DL 1031, check with Delta Air Lines.

DL 1031 lands a B, 7 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 365 flights, with a median arrival 5 minutes early.

Set against the rest of the country, DL 1031's record is 7 points better than the US average of 77.3%. That gap is worth roughly 66 fewer late arrivals for every thousand flights.

On time

83.9%

Arrivals under 15 minutes late, of 360 completed flights

Avg delay

58 min

Across delayed arrivals only, not all flights

Cancelled

1.10%

National rate is 1.89%

1 hour+ late

5.0%

National rate is 8.3%

These figures cover 365 flights between September 2025 and August 2026. The median arrival is 5 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.

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Schedule

When DL 1031 flies

DL 1031 flies ATL to DTW without a single fixed slot. Its most common scheduled departure was 13:00, used on 65 of 365 flights.

Departs 13:0065 flights17.8%

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 13:00 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and DL 1031 runs 6 points better at 83.9%. 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 1031 next to ATL to DTW

Every carrier on ATL to DTW combined arrived on time 76.4% of the time across 4,821 flights, so DL 1031 is 8 points ahead of it. Delta flew 3,774 flights on the same city pair under all its flight numbers, including this one, and those ran 77.9% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight beats by 3 points.

DL 1031 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 1031	365	83.9%	58 min	1.10%	B
All Delta Air Lines on ATL–DTW	3,774	77.9%	60 min	0.50%	B+
All carriers on ATL–DTW	4,821	76.4%	64 min	0.81%	B+
Delta Air Lines, whole network	1,039,517	81.1%	71 min	1.74%	B

Across the year

DL 1031 quarter by quarter

DL 1031 did not run the same all year. Its best quarter was Jul–Sep 2025 at 90.0% on time and its weakest Jul–Sep 2026 at 75.0%, a swing of 15 points on roughly 73 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 flights90.0%
Oct–Dec 202592 flights87.9%
Jan–Mar 202690 flights77.8%
Apr–Jun 202691 flights89.9%
Jul–Sep 202662 flights75.0%

Scale runs 65% to 95%.

By weekday, DL 1031 did best on Wednesday at 94.2% on time and worst on Saturday at 78.8%. Each day rests on about 52 flights, so a gap of 15 points is worth noticing but could still narrow in another year.

Arrival by arrival

How late DL 1031 runs when it is late

The 58 late arrivals split 14 under half an hour, 26 between 30 and 60 minutes, and 18 an hour or more.

15+ min early61 flights16.9%
Within 15 min241 flights66.9%
15–29 min late14 flights3.9%
30–59 min late26 flights7.2%
1–2 hours late13 flights3.6%
2+ hours late5 flights1.4%

Scale runs 0% to 100%.

Share of 360 completed flights by arrival against schedule.

A late pushback is often recovered here: of 72 departures that left 15 minutes late or more, 22 still arrived on time. 8 flights left on time and still arrived late.

The worst days

Worst days for DL 1031

The latest arrival of the period was on 24 July 2026, 4 hours 8 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.

The latest arrivals of DL 1031 in the period
Date	Arrived late by	Largest filed cause
24 July 2026	4 hours 8 minutes	Carrier
11 August 2026	4 hours 2 minutes	Extreme weather
12 May 2026	3 hours 7 minutes	Carrier
22 February 2026	2 hours 13 minutes	Carrier
19 January 2026	2 hours 8 minutes	Extreme weather

Delay causes

Why DL 1031 runs late

Carrier accounts for 58% of the 3,355 delay minutes carriers reported here, and the remaining four split what is left.

Carrier
58%
National Airspace System
16%
Late-arriving aircraft
15%
Extreme weather
10%

The largest share of delay minutes, 58%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,959 of the 3,355 delay minutes reported here. The split is drawn from 3,355 delay minutes reported on DL 1031.

Cancellations sit at 1.10% against a national 1.89%, which is ordinary. Diversions add another 0.27%.

Connections and routes

What a delay on this flight costs

5.0% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.

The 594 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.

Every one of the 365 flights under DL 1031 in the data flew ATL to DTW. 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. 365 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 1031

For a booking, read DL 1031 as 83.9% on time with 1.10% cancelled over 365 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, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures