Abstract Purpose: The main objective of this paper is to determine the annual cyclical flight delays at Hartsfield-Jackson Atlanta International Airport. Then using other data such as annual precipitation, passenger and aircraft traffic volumes and other factors, we attempted to correlate these factors with overall delays. These data could assist airport management in predicting periods of flight delay. Design/methodology/approach: Data were taken and analyzed from the data base “Research and Innovation Technology Administration” (RITA) for the years 2005-2011 for Hartsfield-Jackson Atlanta International Airport. The data included 2.8 million flights originating and departing from this airport. Data were also gathered from the National Oceanic and Atmospheric Administration (NOAA) showing precipitation. Additional data were gathered from the FAA regarding delay causes, number and types of delays and changes to the infrastructure of ATL airport. Findings: T here is a repeatable annual pattern of delays at ATL that can be modelled using delay data from the Bureau of Transportation Statistics. This pattern appears to be caused primarily by the frequency and amount of precipitation that falls at ATL and by the amount of flights that arrive and depart at ATL. Originality/value: This information could assist airport operations personnel, FAA air traffic controllers and airlines in anticipating and mitigating delays at specific times of the year.