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.

Year Percent
1910 2.50%
1911 9.60%
1912 13.80%
1913 13.90%
1914 20.60%
1915 4.80%
1916 5.00%
1917 2.50%
1918 2.20%
1919 8.90%
1920 5.00%
1921 11.30%
1922 4.30%
1923 13.50%
1924 8.80%
1925 4.40%
1926 11.90%
1927 4.80%
1928 7.20%
1929 2.40%
1930 2.30%
1931 6.80%
1932 6.60%
1933 2.30%
1934 11.10%
1935 4.40%
1936 0.00%
1937 6.60%
1938 15.20%
1939 0.00%
1940 6.90%
1941 16.50%
1942 4.90%
1943 11.90%
1944 8.90%
1945 7.00%
1946 4.40%
1947 2.70%
1948 5.20%
1949 11.20%
1950 11.70%
1951 20.10%
1952 17.60%
1953 17.60%
1954 8.80%
1955 2.30%
1956 6.60%
1957 15.20%
1958 6.90%
1959 18.00%
1960 22.20%
1961 15.90%
1962 6.40%
1963 4.80%
1964 8.80%
1965 9.20%
1966 13.00%
1967 6.60%
1968 20.10%
1969 0.00%
1970 9.00%
1971 6.50%
1972 19.60%
1973 7.00%
1974 2.30%
1975 6.60%
1976 4.60%
1977 4.60%
1978 28.20%
1979 4.50%
1980 21.30%
1981 15.50%
1982 11.20%
1983 4.40%
1984 15.00%
1985 12.90%
1986 27.20%
1987 6.70%
1988 9.70%
1989 9.10%
1990 15.40%
1991 21.70%
1992 2.30%
1993 19.80%
1994 11.10%
1995 8.50%
1996 6.60%
1997 10.80%
1998 13.40%
1999 28.40%
2000 15.70%
2001 4.30%
2002 21.30%
2003 6.70%
2004 11.20%
2005 6.80%
2006 11.00%
2007 25.90%
2008 16.50%
2009 9.60%
2010 45.50%
2011 5.00%
2012 13.90%
2013 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.