Route reliability record
ATL→EYW
Atlanta to Key West
- Flights
- 1,460
- Period
- September 2025 to August 2026
- Distance
- 646 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 1,460 ATL to EYW flights, with a median arrival 9 minutes early.
Best time to fly ATL to EYW: a 8am–11am departure, ideally on a Thursday. Flights in that window arrived on time 90.1% of the time and Thursday flights 91.6%, against 83.0% for the route overall.
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 1,424 completed flights
Avg delay
72 min
Across delayed arrivals only, not all flights
Cancelled
1.58%
National rate is 1.89%
Best carrier
Delta
83.0% on time across 1,460 flights
These figures cover 1,460 flights between September 2025 and August 2026. The median arrival is 9 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 ATL to EYW
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 | 1,460 | 83.0% | 72 min | 1.58% | B |
Flight by flight
Flights on ATL to EYW
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 13 points, against half a point between the best and worst carrier.
- 5am–8am—
- 8am–11am415 flights90.1%
- 11am–2pm337 flights86.0%
- 2pm–5pm343 flights77.8%
- 5pm–8pm365 flights77.2%
- 8pm–5am—
Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 90.1% of the time, against 77.2% for the evening window. That is 13 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 415 flights scheduled in it.
Explore
Filter ATL to EYW 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 ATL to EYW, the best departure window is 8am–11am at 90.1% on time and the worst is 5pm–8pm at 77.2%, a wide gap of 12.9 points. All US flights leaving 8am–11am ran 83.9%.
- 5–8am—
- 8–11am90.1%
- 11am–2pm86.0%
- 2–5pm77.8%
- 5–8pm77.2%
- 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 25 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.
December is the weak month at 70.0% on time, against 95.0% 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. May was the busiest month here, with 127 flights.
Across the week, Thursday is the strongest day at 91.6% on time and Sunday the weakest at 73.8%, a spread of 18 points.
Delay causes
Why this route gets delayed
Carrier accounts for 45% of the 17,000 delay minutes carriers reported here, and the remaining four split what is left.
- 45%Carrier
- 20%National Airspace System
- 20%Extreme weather
- 15%Late-arriving aircraft
Extreme weather accounts for 20% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 3.3 times the usual weather exposure. The split is drawn from 17,349 reported delay minutes.
The largest share of delay minutes, 45%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 7,805 of the 17,000 delay minutes reported here.
Cancellations sit at 1.58% against a national 1.89%, which is ordinary. Diversions add another 0.89%.
Connections and stage length
What a delay here actually costs
5.9% 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.
The 646 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 return leg is a different operation and performs like one: it runs 86.1% on time across 1,460 flights, 3 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 3 points of difference.
The sample behind these figures is 1,460 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.
Work out the risk of missing a connection in EYW after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 95.0% on time and December 70.0%, a swing of 25 points. If the dates move at all, move them out of December before you think about anything else. 1,424 completed flights over 12 months sit behind that.
Common questions
ATL to EYW questions
How often is ATL to EYW 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 1,460 flights in this analysis, against 22.7% nationally. Delayed flights are late by a little over an hour on average.
How reliable is ATL to EYW 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 ATL to EYW?
The 8am–11am departure window is the strongest at 90.1% on time. The 5pm–8pm window is the weakest at 77.2%, 13 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 December delays on ATL to EYW?
December is the weakest month at 70.0% on time, compared with 95.0% in September. Across the year that is 25 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
- EYW to ATL — the return legseparate record
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- ATL to LGA, a related route72.3%
- MIA to EYW, a related route86.8%
- ATL to MCO, a related route70.3%
- Delta Air Lines on-time record83.0%
- The best time of day to fly, according to 7.05 million flight records
- Worst months to fly in the US, ranked by the data
Direction matters. ATL to EYW and EYW to ATL 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.