Route reliability record
STT→ATL
Charlotte Amalie to Atlanta
- Flights
- 719
- Period
- September 2025 to August 2026
- Distance
- 1,599 mi
- Carriers
- 1
This route lands a B, 6 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 a little over an hour on average. That rests on 719 STT to ATL flights, with a median arrival 12 minutes early.
Set against the rest of the country, this route's record is 6 points better than the US average of 77.3%. That gap is worth roughly 57 fewer late arrivals for every thousand flights.
Key figures
On time
83.0%
Arrivals under 15 minutes late, of 687 completed flights
Avg delay
78 min
Across delayed arrivals only, not all flights
Cancelled
1.95%
National rate is 1.89%
Best carrier
Delta
83.0% on time across 719 flights
These figures cover 719 flights between September 2025 and August 2026. The median arrival is 12 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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Carrier by carrier
Which airline is most reliable on STT to ATL
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 | 719 | 83.0% | 78 min | 1.95% | B |
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Departure window
The best time of day to leave
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 719 flights.
- 5am–8am—
- 8am–11am—
- 11am–2pm158 flights80.5%
- 2pm–5pm552 flights83.7%
- 5pm–8pm9 flights—
- 8pm–5am—
Scale runs 70% to 90%. Rows with fewer than 30 flights show a dash.
The 2pm–5pm window is the strongest at 83.7% on time. The full set of windows spans 3 points.
Explore
Filter STT to ATL by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On STT to ATL, the best departure window is 2pm–5pm at 83.7% on time and the worst is 11am–2pm at 80.5%, a narrow gap of 3.2 points. All US flights leaving 2pm–5pm ran 71.9%.
- 5–8am—
- 8–11am—
- 11am–2pm80.5%
- 2–5pm83.7%
- 5–8pm—
- 8pm–5am—
best all US flightsScale 60% to 95%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 20 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
August is the worst month at 73.7% on time, 20 points below September, the best at 94.1%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. March was the busiest month here, with 93 flights.
Across the week, Thursday is the strongest day at 89.7% on time and Sunday the weakest at 74.2%, a spread of 16 points.
Delay causes
Why this route gets delayed
Carrier accounts for 45% of the 9,141 delay minutes carriers reported here, and the remaining four split what is left.
- 45%Carrier
- 42%Late-arriving aircraft
- 10%National Airspace System
- 3%Extreme weather
42% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 9,141 reported delay minutes here, that single category outweighs weather by 13 to one. The split is drawn from 9,141 reported delay minutes.
The largest share of delay minutes, 45%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 4,074 of the 9,141 delay minutes reported here.
Cancellations sit at 1.95% against a national 1.89%, which is ordinary. Diversions add another 2.50%.
Connections and stage length
What a delay here actually costs
6.1% 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 a little over an hour, which a normal layover absorbs.
At 1,599 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.
The return leg is a different operation and performs like one: it runs 76.4% on time across 719 flights, 7 points below 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 7 points of difference.
One caution: this is a thin sample. 719 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.
Work out the risk of missing a connection in ATL after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 719 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 83.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 687 completed flights over 12 months sit behind that.
Common questions
STT to ATL questions
How often is STT to ATL delayed?
About one flight in six arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 17.0% of the 719 flights in this analysis, against 22.7% nationally. Delayed flights are late by a little over an hour on average.
How reliable is STT to ATL compared with the rest of the country?
83.0% of flights arrive on time here against a national 77.3%, a difference of 6 points in its favour. That is worth a B on this site's grading scale.
What time of day has the fewest delays on STT to ATL?
The 2pm–5pm departure window is the strongest at 83.7% on time. The 11am–2pm window is the weakest at 80.5%, 3 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are August delays on STT to ATL?
August is the weakest month at 73.7% on time, compared with 94.1% in September. Across the year that is 20 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- ATL to STT — the return legseparate record
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- STT to MIA, a related route81.9%
- LGA to ATL, a related route75.5%
- MCO to ATL, a related route74.9%
- Delta Air Lines on-time record83.0%
- Why the first flight of the morning is statistically safest
- Worst months to fly in the US, ranked by the data
Direction matters. STT to ATL and ATL to STT are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.