The 2012–13 North American drought, an expansion of the 2010–13 Southern United States drought, originated in the midst of a record-breaking heat wave. Low snowfall amounts in winter, coupled with the intense summer heat from La Niña, caused drought-like conditions to migrate northward from the southern United States, wreaking havoc on crops and water supply. The drought has inflicted, and is expected to continue to inflict, catastrophic economic ramifications for the affected states. It has exceeded, in most measures, the 1988–89 North American drought, the most recent comparable drought, and is on track to exceed that drought as the costliest natural disaster in U.S. history.
The drought includes most of the U.S., parts of Mexico, and central and Eastern Canada. At its peak on July 17, 2012, it covered approximately 81 percent of the contiguous United States with at least abnormally dry (D0) conditions. Out of that 81%, 64% was designated as at least moderate drought (D1) conditions. Its area was comparable to the droughts in the 1930s and 1950s but it has not yet been in place for as long. In March 2013, heavy winter rains broke a three-year pattern of drought in much of the Southeastern United States, while drought conditions still plague the Great Plains and other parts of the U.S., according to the U.S. Drought Monitor.
Drought continued in parts of North America through 2013. Beginning in March 2013, improved rainfall across the Midwest, southern Mississippi Valley, and Great Plains began gradually alleviating drought in these areas, while drought continued to intensify in the Western United States. Heavy rains across previously drought-stricken areas resulted in widespread flooding in portions of the Midwest, a phenomenon which was named "weather whiplash". By June 2013, approximately the eastern half of the United States was drought-free, while conditions continued to gradually improve across the Plains. Moderate to severe drought continues to impact and worsen throughout the western United States, with some portions of the United States being afflicted by the drought for over three years. Through the winter of 2013–2014, California continued to receive record low rainfall. For many locations, the calendar year of 2013 was the driest year in over 130 years. Some locations received less than half of their previous record low rainfall amounts.