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Data & Maps

Historical Data and Conditions

By looking back at historical data, communities can get a better understanding of the drought and extreme weather threats to be prepared for. The resources below help document and quantify historical drought conditions in order to help inform planning. Three historical drought datasets can be explored side by side: the U.S. Drought Monitor (weekly, 2000–present); Standardized Precipitation Index (monthly, 1895–present); and June-July-August Palmer Modified Drought Index values from tree-ring reconstructions and instrumental data (yearly, 0–2017).

54.8%

of the U.S. was in drought in September 2012, according to the U.S. Drought Monitor record since 2000

66.2%

of the lower 48 states were in drought in Summer 1934, the most in the lower 48, according to the Living Blended Drought Product since year 0

22.9%

of the U.S. was in Exceptional Drought (D4) in February 1977, according to the Standardized Precipitation Index (SPI) since 1895

82.3%

of the U.S. was Abnormally Wet in May 2019, the most according to the Standardized Precipitation Index (SPI) since 1895

Explore Historical Drought Conditions

U.S. Drought Monitor Category
Value Map Hex Color % of U.S. Description
D0 - Abnormally Dry #FFFF37 0 Abnormally Dry Abnormally Dry (D0) indicates a region that is going into or coming out of drought. 
D1 - Moderate Drought #FCD37F 0 Moderate Drought Moderate Drought (D1) is the first of four drought categories (D1–D4), according to the U.S. Drought Monitor.
D2 - Severe Drought #FFAA27 0 Severe Drought Severe Drought (D2) is the second of four drought categories (D1–D4), according to the U.S. Drought Monitor.
D3 - Extreme Drought #E60C14 0 Extreme Drought Extreme Drought (D3) is the third of four drought categories (D1–D4), according to the U.S. Drought Monitor.
D4 - Exceptional Drought #730305 0 Exceptional Drought Exceptional Drought (D4) is the most intense drought category, according to the U.S. Drought Monitor.
Total Area in Drought (D1–D4) dmtotal 0 Total Area in Drought (D1–D4) Percent area of the 50 U.S. states and Puerto Rico that is currently in drought (D1–D4), according to the U.S. Drought Monitor.

The U.S. Drought Monitor (2000–present) depicts the location and intensity of drought across the country. Every Thursday, authors from NOAA, USDA, and the National Drought Mitigation Center produce a new map based on their assessments of the best available data and input from local observers. The map uses five categories: Abnormally Dry (D0), showing areas that may be going into or are coming out of drought, and four levels of drought (D1–D4). Learn more.

Time Period (Years): to

SOURCE(S):

NOAA, USDA, National Drought Mitigation Center