Flight number record

DL 2051

Delta Air Lines · Atlanta to Houston

Route: ATL → HOU
Departs: 21:15
Flights: 365
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 2051, check with Delta Air Lines.

DL 2051 sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 365 flights, with a median arrival 4 minutes early.

On time

74.2%

Arrivals under 15 minutes late, of 361 completed flights

Avg delay

56 min

Across delayed arrivals only, not all flights

Cancelled

0.82%

National rate is 1.81%

1 hour+ late

8.0%

National rate is 8.1%

These figures cover 365 flights between July 2025 and June 2026. Beyond the headline rate, 8.0% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Schedule

When DL 2051 flies

DL 2051 flies ATL to HOU without a single fixed slot. Its most common scheduled departure was 21:15, used on 80 of 365 flights, with 21:54 (51 flights) and 21:20 (40 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 21:1580 flights21.9%
Departs 21:5451 flights14.0%
Departs 21:2040 flights11.0%

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 21:15 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.5%, and DL 2051 runs 4 points better at 74.2%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

Against the route

DL 2051 next to ATL to HOU

Every carrier on ATL to HOU combined arrived on time 80.5% of the time across 2,915 flights, so DL 2051 is 6 points behind it. Delta flew 1,416 flights on the same city pair under all its flight numbers, including this one, and those ran 81.2% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 7 points.

DL 2051 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 2051	365	74.2%	56 min	0.82%	C+
All Delta Air Lines on ATL–HOU	1,416	81.2%	56 min	1.77%	B
All carriers on ATL–HOU	2,915	80.5%	57 min	1.20%	B
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 2051 quarter by quarter

DL 2051 did not run the same all year. Its best quarter was Jan–Mar 2026 at 81.4% on time and its weakest Oct–Dec 2025 at 69.6%, a swing of 12 points on roughly 91 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 flights75.0%
Oct–Dec 202592 flights69.6%
Jan–Mar 202690 flights81.4%
Apr–Jun 202691 flights71.4%

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

By weekday, DL 2051 did best on Wednesday at 80.8% on time and worst on Thursday at 65.4%. Each day rests on about 52 flights, so a gap of 15 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 2051 runs late

One category carries most of the weight here. Carrier accounts for 51% of the 5,233 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
51%
Late-arriving aircraft
33%
National Airspace System
11%
Extreme weather
5%

The largest share of delay minutes, 51%, 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 2,684 of the 5,233 delay minutes reported here. The split is drawn from 5,233 delay minutes reported on DL 2051.

Cancellations are rare at 0.82%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Connections and routes

What a delay on this flight costs

8.0% 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 about an hour, which a normal layover absorbs.

The 696 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

Every one of the 365 flights under DL 2051 in the data flew ATL to HOU. 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 2051

For a booking, DL 2051 is one of the weaker ways to fly ATL to HOU: 6 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.

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