Carrier route record
DLATL→STL
Delta Air Lines · Atlanta to St. Louis
- Flights
- 2,371
- Period
- July 2025 to June 2026
- Share of route
- 64%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on ATL to STL earns a B. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 2,371 flights, with a median arrival 7 minutes early.
Set against the rest of the country, Delta's ATL to STL record is 7 points better than the US average of 77.6%. That gap is worth roughly 71 fewer late arrivals for every thousand flights.
Key figures
On time
84.7%
Arrivals under 15 minutes late, of 2,317 completed flights
Avg delay
55 min
Across delayed arrivals only, not all flights
Cancelled
1.98%
National rate is 1.81%
Whole route
82.4%
Every carrier on ATL to STL, 3,706 flights
These figures cover 2,371 flights between July 2025 and June 2026. The median arrival is 7 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.
Carrier by carrier
Delta against every carrier on ATL to STL
Delta flew 2,371 of the 3,706 flights on ATL to STL, most of the route. Its 84.7% on time is 2 points better than the route as a whole, which runs 82.4%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Delta at 84.7% to Frontier at 69.7%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines (this page) | 2,371 | 84.7% | 55 min | 1.98% | B |
| Southwest Airlines | 1,130 | 79.9% | 56 min | 0.53% | B+ |
| Frontier Airlinesthin sample | 205 | 69.7% | 57 min | 1.95% | C |
Flight by flight
Delta flight numbers on ATL to STL
Departure window
When Delta runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 15 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am161 flights92.4%
- 8am–11am470 flights89.5%
- 11am–2pm286 flights86.2%
- 2pm–5pm501 flights88.4%
- 5pm–8pm349 flights80.4%
- 8pm–5am604 flights77.6%
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 92.4% of the time, against 77.6% for the overnight window. That is 15 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 604 flights scheduled in it.
Across the year
Delta on ATL to STL through the year
February is the weak month at 78.3% on time, against 95.7% in September. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. July was the busiest month here, with 224 flights.
Across the week, Wednesday is the strongest day at 89.5% on time and Sunday the weakest at 80.4%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Delta runs late on this route
One category carries most of the weight here. Carrier accounts for 54% of the 20,000 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.
- 54%Carrier
- 26%Late-arriving aircraft
- 15%National Airspace System
- 6%Extreme weather
- 0%Security
The largest share of delay minutes, 54%, 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 10,000 of the 20,000 delay minutes reported here. The split is drawn from 19,568 reported delay minutes.
Cancellations sit at 1.98% against a national 1.81%, which is ordinary. Diversions add another 0.30%.
Connections and stage length
What a delay here costs
Badly late arrivals are rare here: only 4.5% land an hour or more behind schedule, against 8.1% 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.
At 484 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 89.4% on time across 2,371 flights, 5 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 5 points of difference.
The sample behind these figures is 2,371 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking Delta on ATL to STL
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 95.7% on time and February 78.3%, a swing of 17 points. If the dates move at all, move them out of February before you think about anything else. 2,317 completed flights over 12 months sit behind that.
Related
Where to go next
- ATL to STL, every carrier
- Delta on STL to ATL, the return leg
- Southwest Airlines on ATL to STL79.9%
- Frontier Airlines on ATL to STL69.7%
- Delta Air Lines network-wide record
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- St. Louis Lambert International (STL) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
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.