Flight number record

DL 1100

Delta Air Lines · Philadelphia to Atlanta

Route: PHL → ATL
Departs: 10:30
Flights: 290
Period: September 2025 to August 2026

Historical statistics for September 2025 to August 2026, not live status. For today’s DL 1100, check with Delta Air Lines.

DL 1100 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 40 minutes on average. That rests on 290 flights, with a median arrival 10 minutes early.

Set against the rest of the country, DL 1100'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 279 completed flights

Avg delay

41 min

Across delayed arrivals only, not all flights

Cancelled

3.45%

National rate is 1.89%

1 hour+ late

2.5%

National rate is 8.3%

These figures cover 290 flights between September 2025 and August 2026. The median arrival is 10 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.

Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.

Schedule

When DL 1100 flies

DL 1100 flies PHL to ATL without a single fixed slot. Its most common scheduled departure was 10:30, used on 60 of 290 flights, with 10:40 (49 flights) and 10:28 (33 flights) next.

Departs 10:3060 flights20.7%
Departs 10:4049 flights16.9%
Departs 10:2833 flights11.4%

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 10:30 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and DL 1100 runs level with that at 83.9%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.

Against the route

DL 1100 next to PHL to ATL

Every carrier on PHL to ATL combined arrived on time 78.0% of the time across 5,793 flights, so DL 1100 is 6 points ahead of it. Delta flew 3,022 flights on the same city pair under all its flight numbers, including this one, and those ran 83.2% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight beats by 3 points.

DL 1100 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 1100thin sample	290	83.9%	41 min	3.45%	B−
All Delta Air Lines on PHL–ATL	3,022	83.2%	70 min	3.11%	B−
All carriers on PHL–ATL	5,793	78.0%	71 min	3.11%	B−
Delta Air Lines, whole network	1,039,517	81.1%	71 min	1.74%	B

Across the year

DL 1100 quarter by quarter

DL 1100 did not run the same all year. Its best quarter was Apr–Jun 2026 at 91.1% on time and its weakest Jul–Sep 2026 at 71.4%, a swing of 20 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 202529 flights—
Oct–Dec 202568 flights84.8%
Jan–Mar 202683 flights79.7%
Apr–Jun 202657 flights91.1%
Jul–Sep 202653 flights71.4%

Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, DL 1100 did best on Wednesday at 95.5% on time and worst on Monday at 74.4%. Each day rests on about 41 flights, so a gap of 21 points is worth noticing but could still narrow in another year.

Arrival by arrival

How late DL 1100 runs when it is late

DL 1100 often beats the schedule: 103 of 279 completed flights, 37%, arrived 15 minutes or more early. The 45 late arrivals split 22 under half an hour, 16 between 30 and 60 minutes, and 7 an hour or more.

15+ min early103 flights36.9%
Within 15 min131 flights47.0%
15–29 min late22 flights7.9%
30–59 min late16 flights5.7%
1–2 hours late5 flights1.8%
2+ hours late2 flights0.7%

Scale runs 0% to 100%.

Share of 279 completed flights by arrival against schedule.

8 of 39 late departures made up the time and arrived on time, 21% of them. In the other direction, 14 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 ATL.

The worst days

Worst days for DL 1100

The latest arrival of the period was on 7 December 2025, 2 hours 54 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. On four of the five worst days the largest share was filed as a late-arriving aircraft.

The latest arrivals of DL 1100 in the period
Date	Arrived late by	Largest filed cause
7 December 2025	2 hours 54 minutes	National Airspace System
29 March 2026	2 hours 26 minutes	Late-arriving aircraft
25 November 2025	1 hour 58 minutes	Late-arriving aircraft
16 March 2026	1 hour 26 minutes	Late-arriving aircraft
26 January 2026	1 hour 19 minutes	Late-arriving aircraft

Delay causes

Why DL 1100 runs late

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 1,833 reported delay minutes.

Late-arriving aircraft
41%
National Airspace System
30%
Carrier
26%
Extreme weather
3%

41% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 1,833 reported delay minutes here, that single category outweighs weather by 13 to one. The split is drawn from 1,833 delay minutes reported on DL 1100.

Cancellations run at 3.45%, against 1.89% nationally. That is about one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 2.5% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

The 666 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.

The same number turns up on three other city pairs in the data, including ATL to PHL (219), MSP to DFW (31) and ATL to RDU (12), but none flew often enough under DL 1100 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to PHL to ATL only.

One caution: this is a thin sample. 290 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 1100

For a booking, the cancellation rate is the figure to plan around on DL 1100: 3.45% of its 290 scheduled flights did not operate. A late arrival costs about 40 minutes, but a cancellation costs the day, so leave a later option open.

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