Airlines Departure Delay Prediction (Regression). Original data can be found at: http://www.transtats.bts.gov
This is a processed version of the original data, designed to predict departure delay (in seconds).
A CSV of the raw data (years 1987-2013) can be be found here. This is the first 10 million rows (and a subset of the columns) of this CSV file, in ARFF format.