Louisville, KY

What the Data Says About SDF

Louisville, KY in Louisville, Kentucky handled 252,784 flights in the Bureau of Transportation Statistics dataset between 2020 and 2025, posting a 82.8% on-time departure rate. Of those flights, 43,419 experienced delays, 3,127 were cancelled, and 294 were diverted. The cancellation rate works out to 1.24%, the diversion rate to 0.12%, and the average delay when departures run late is 78.6 minutes. These figures are the baseline for comparing SDF against other airports in the same state and nationally.

Breaking down what drives delays at SDF, Carrier leads the pack. Carrier accounts for 38.1% of total delay minutes, followed by Late Aircraft at 33.8% and NAS (National Aviation System) at 21.6%. Weather contributes 6.3% of delay minutes at this airport, while security holds the smallest share at 0.2%. Travelers often overestimate the weather share; the BTS categorization shows late-arriving aircraft and carrier operations as the larger contributors.

Seasonally, September runs the cleanest at SDF with a 94% on-time rate, while July is the roughest at 89.7% — a 4-point swing between best and worst month. Volume peaks in July, when average flights hit 3,850. The busiest route from SDF is to ATL (Atlanta), with 16,538 flights at a 89.5% on-time rate. Combine these numbers — 82.8% on-time, 78.6-minute average delay, 1.24% cancellation rate — and you have a concrete picture of departure reliability at Louisville, KY.