Impacts of weather and climate conditions are defined for most unusual events such as major floods, droughts, cold or warm winters, and heat waves. We examine both the physical effects, such as changes in streamflow, ground water levels, and crop yields, and the socio-economic impacts caused by these events. Some recent impact studies include the July 1999 heat wave in the Midwest, the 1999 New Year's Day Blizzard, and the 1997-1998 El Niño.

Also See: Environmental and Societal Impacts of Weather and Climate