The diurnal temperature ranges (DTRs) in the Southeastern United States have a wide distribution of magnitudes, and patterns in this distribution are witnessed on both spatial and temporal scales. Rapid or intense changes in daily temperatures can create heat/cold stress on animals; therefore an accurate prediction of these climate-driven fluctuations will be helpful for the equestrian and cattle industries. In addition to seasonal and annual distributions, DTRs also vary with respect to the climatological phase of the El Niņo Southern Oscillation (ENSO). It is well documented that ENSO has impacts on temperatures in the Southeast US, especially in the winter months. A 62-year record of quality-controlled observations collected from the National Weather Service's Cooperative Observing Network (COOP) is being used for analysis. Cumulative Probability distribution functions (PDFs), Relative Frequencies (RFs), and ratios between phase RFs, will be applied to show that DTRs vary in response to El Niņo or La Niņa with statistical significance. These varied responses will be shown both temporally and spatially across the region. Results will show that the distribution of DTRs during La Niņa is significantly shifted towards higher values, while the distribution of DTRs during El Niņo is significantly shifted towards lower values or extremely high values, during winter and spring. Statistical results will show that El Niņo is more significant overall. These results allow seasonal predictability of the extreme DTR events depending upon the current (or expected) phase of ENSO.