The REDTI and MSI: Two New National Climate Impact Indices

Abstract

Two climate indices that are useful for monitoring the impact of weather and climate on energy usage and crop yields in the United States have been developed at the National Climatic Data Center. The residential energy-demand temperature index (REDTI), which is based on total population-weighted heating and cooling degree days in the contiguous United States, provides quantitative information on the impact of seasonal temperatures on residential energy demand. The moisture stress index (MSI) is based on the effect of severe to catastrophic drought (Palmer Z index values ≤?2) or catastrophic wetness (Z ≥ +5) on crop productivity within two crop-growing regions (corn and soybeans). Using climate data that extends into the late nineteenth century and operational updates of near-real-time data, the indices provide information that places the impact of weather and climate on energy-supply and crop-production sectors of the economy during the most recent season into historical perspective.