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DelayAtlas

Route reliability record

SDFLGA

Louisville to New York

Flights
1,063
Period
July 2025 to June 2026
Distance
659 mi
Carriers
3
B−GRADE

This route carries a cancellation problem, not just a delay problem: 4.3% of scheduled flights never operate, against 1.8% nationally. Of the ones that do fly, more than four flights in five arrive on time, worth a B− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 1,063 SDF to LGA flights, with a median arrival 12 minutes early.

Best time to fly SDF to LGA: a 5am–8am departure, ideally on a Saturday. Flights in that window arrived on time 90.8% of the time and Saturday flights 86.2%, against 83.1% for the route overall.

Set against the rest of the country, this route's record is 6 points better than the US average of 77.6%. That gap is worth roughly 55 fewer late arrivals for every thousand flights.

Key figures

On time

83.1%

Arrivals under 15 minutes late, of 1,014 completed flights

Avg delay

63 min

Across delayed arrivals only, not all flights

Cancelled

4.33%

National rate is 1.81%

Best carrier

Republic

83.5% on time across 1,027 flights

These figures cover 1,063 flights between July 2025 and June 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.

Carrier by carrier

Which airline is most reliable on SDF to LGA

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.

On-time performance by carrier on SDF to LGA
AirlineFlightsOn timeAvg delayCancelledGrade
Republic Airways1,02783.5%61 min3.80%B−
SkyWest Airlinesthin sample3575.0%97 min20.00%B−
American Airlinesthin sample10.0%137 min0.00%F+

Best ways to make this trip

The most reliable ways to fly Louisville to New York

Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 1 of the top 2 use a different airport at one end.

Most reliable ways to fly from SDF to LGA
OptionAirlineSuccessOn timeCancelledBest departureMost punctual flight
1. SDFEWRLouisville to NewarkRepublic Airways83.2%86.4%3.76%8am–11am, Wed (route)YX 3594 06:15
2. SDFLGALouisville to New YorkRepublic Airways80.3%83.5%3.80%5am–8am, Sat (route)

Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.

Plan this trip by month, day and time

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 14 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–8am359 flights90.8%
  • 8am–11am59 flights87.7%
  • 11am–2pm220 flights80.3%
  • 2pm–5pm228 flights78.0%
  • 5pm–8pm197 flights76.5%
  • 8pm–5am

Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 90.8% of the time, against 76.5% for the evening window. That is 14 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 359 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 22 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.

On-time rate by calendar month85J78F75M84A86M88J83J90A93S84O76N71D
Darker means more delays. Figures are on-time percentages.September best, December worst

December is the weak month at 70.8% on time, against 92.8% 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 116 flights.

Across the week, Saturday is the strongest day at 86.2% on time and Thursday the weakest at 79.7%. 7 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week83.9Mon81.0Tue84.8Wed79.7Thu85.5Fri86.2Sat81.9Sun
Monday: 83.9 percent on time. Tuesday: 81.0 percent on time. Wednesday: 84.8 percent on time. Thursday: 79.7 percent on time. Friday: 85.5 percent on time. Saturday: 86.2 percent on time. Sunday: 81.9 percent on time

Delay causes

Why this route gets delayed

One category carries most of the weight here. National Airspace System accounts for 43% of the 11,000 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.

  • National Airspace System
    43%
  • Carrier
    34%
  • Late-arriving aircraft
    16%
  • Extreme weather
    6%

The largest share of delay minutes, 34%, 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 3,694 of the 11,000 delay minutes reported here. The split is drawn from 10,785 reported delay minutes.

43% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 4,649 minutes out of 11,000, against a national NAS share of 21%.

Cancellations run at 4.33%, against 1.81% nationally. That is about one flight in 25 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 stage length

What a delay here actually costs

6.6% 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 659 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.

The return leg is a different operation and performs like one: it runs 79.8% on time across 1,062 flights, 3 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 3 points of difference.

One caution: this is a thin sample. 1,063 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 LGA after this flight

What to do with this

Booking this route

Put together: the delay figures matter less here than the 4.33% cancellation rate. A late arrival costs you about an hour; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 1,014 completed flights over 12 months sit behind that.

Common questions

SDF to LGA questions

How often is SDF to LGA 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 16.9% of the 1,063 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

How reliable is SDF to LGA compared with the rest of the country?

83.1% of flights arrive on time here against a national 77.6%, 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 SDF to LGA?

The 5am–8am departure window is the strongest at 90.8% on time. The 5pm–8pm window is the weakest at 76.5%, 14 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 SDF to LGA?

December is the weakest month at 70.8% on time, compared with 92.8% in September. Across the year that is 22 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

Direction matters. SDF to LGA and LGA to SDF are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Embed SDF to LGA’s on-time badge on your site

Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.

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.