U.S. Climate Extremes Index (CEI)

NCDC transitioned to the nClimDiv dataset on Thursday, March 13, 2014. This was coincident with the release of the February 2014 monthly monitoring report. For details on this transition, please visit our public FTP site and our U.S. Climate Divisional Database site.

Graph

Choose a period/season and an indicator from the options below and click "Plot" to create a time series graph. Note that the sixth indicator (Step 6) is not calculated for the spring (March-May), winter (December-February) and cold (October-March) seasons since most months during these periods are outside of the traditional hurricane season.



Move mouse towards an axis until highlighted. Left-click mouse to pan. Shift key + left-click to zoom.

Download: Wet Data | Dry Data
Year Wet Dry
1910 9.30% 14.70%
1911 13.60% 11.50%
1912 9.20% 5.90%
1913 3.80% 26.80%
1914 5.70% 8.80%
1915 29.40% 11.80%
1916 8.20% 13.30%
1917 2.10% 24.80%
1918 0.00% 17.70%
1919 22.30% 6.70%
1920 8.10% 0.00%
1921 6.70% 3.60%
1922 2.40% 15.30%
1923 8.20% 7.00%
1924 1.10% 35.20%
1925 0.00% 11.90%
1926 2.20% 6.50%
1927 11.90% 0.00%
1928 26.30% 4.60%
1929 0.00% 17.10%
1930 0.00% 34.40%
1931 5.60% 8.60%
1932 4.40% 2.30%
1933 1.10% 5.40%
1934 0.00% 40.20%
1935 6.70% 5.20%
1936 0.00% 49.90%
1937 4.50% 2.30%
1938 1.10% 5.40%
1939 4.40% 1.10%
1940 21.60% 1.00%
1941 23.70% 0.00%
1942 15.50% 0.00%
1943 0.00% 24.80%
1944 3.20% 4.70%
1945 11.40% 4.70%
1946 1.20% 11.50%
1947 0.00% 18.00%
1948 10.90% 10.40%
1949 24.40% 0.00%
1950 35.00% 0.00%
1951 19.80% 5.70%
1952 0.00% 22.50%
1953 0.00% 10.50%
1954 1.00% 39.20%
1955 8.80% 2.00%
1956 1.00% 20.20%
1957 2.10% 5.60%
1958 12.10% 3.50%
1959 29.70% 0.00%
1960 12.00% 1.00%
1961 18.80% 0.00%
1962 13.50% 0.00%
1963 1.10% 3.40%
1964 2.20% 6.80%
1965 11.30% 5.50%
1966 2.10% 4.30%
1967 10.30% 2.20%
1968 12.50% 0.00%
1969 3.10% 5.40%
1970 2.10% 9.80%
1971 18.50% 1.00%
1972 6.70% 1.10%
1973 18.80% 0.00%
1974 6.80% 4.30%
1975 26.40% 4.10%
1976 8.90% 26.80%
1977 4.20% 0.00%
1978 1.00% 4.10%
1979 16.10% 0.00%
1980 0.00% 60.70%
1981 14.30% 4.20%
1982 4.50% 6.10%
1983 3.40% 13.00%
1984 5.50% 8.40%
1985 3.20% 4.40%
1986 6.80% 0.00%
1987 7.90% 0.00%
1988 2.30% 6.30%
1989 34.60% 0.00%
1990 0.00% 9.60%
1991 13.40% 2.10%
1992 37.60% 1.20%
1993 13.20% 5.40%
1994 3.40% 9.00%
1995 0.00% 3.40%
1996 46.10% 0.00%
1997 7.60% 1.20%
1998 1.10% 13.00%
1999 2.40% 5.30%
2000 0.00% 13.70%
2001 3.40% 9.50%
2002 2.40% 5.40%
2003 19.50% 1.00%
2004 35.50% 0.00%
2005 5.70% 3.40%
2006 7.80% 10.20%
2007 38.80% 5.70%
2008 10.00% 1.10%
2009 15.00% 11.70%
2010 7.10% 5.60%
2011 1.10% 49.50%
2012 2.40% 19.00%
2013 3.60% 2.50%
2014 4.90% 0.00%

*As of September 2005, the fourth and fifth indicators are computed with data from one station per each grid box rather than multiple stations. This was done to eliminate many of the artificial extremes which resulted from a changing number of available stations over time. Therefore, the percentages in the step 4 and 5 graphs above will likely be significantly different from the percentages calculated prior to the changes implemented in September 2005.

View CEI Data Files

Limitations: Statistics for the most recent period/season are computed from a fraction of the U.S. which has data available at that time. Extreme percentage values can and will likely change as final quality controlled data become available and fill in the data gaps.