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 7.90%
1912 11.50%
1913 4.80%
1914 15.30%
1915 11.20%
1916 5.50%
1917 11.00%
1918 13.00%
1919 3.40%
1920 3.20%
1921 12.40%
1922 4.70%
1923 10.40%
1924 4.30%
1925 11.40%
1926 4.40%
1927 4.40%
1928 10.70%
1929 5.40%
1930 8.70%
1931 13.90%
1932 10.70%
1933 15.30%
1934 5.50%
1935 6.40%
1936 23.00%
1937 4.40%
1938 9.70%
1939 6.30%
1940 8.40%
1941 12.30%
1942 5.40%
1943 7.50%
1944 4.30%
1945 13.50%
1946 14.00%
1947 11.50%
1948 4.40%
1949 3.10%
1950 14.80%
1951 7.30%
1952 4.20%
1953 10.70%
1954 7.50%
1955 3.10%
1956 4.30%
1957 6.40%
1958 7.60%
1959 2.10%
1960 11.90%
1961 6.30%
1962 1.00%
1963 7.60%
1964 4.50%
1965 6.30%
1966 9.20%
1967 5.30%
1968 3.20%
1969 2.20%
1970 7.20%
1971 7.20%
1972 4.10%
1973 4.20%
1974 12.10%
1975 11.20%
1976 6.20%
1977 4.10%
1978 13.60%
1979 8.70%
1980 16.10%
1981 12.60%
1982 7.90%
1983 6.60%
1984 5.30%
1985 18.00%
1986 8.40%
1987 6.50%
1988 5.50%
1989 13.80%
1990 9.70%
1991 11.60%
1992 5.60%
1993 14.70%
1994 5.40%
1995 14.30%
1996 6.20%
1997 11.30%
1998 10.60%
1999 18.20%
2000 11.10%
2001 18.30%
2002 11.20%
2003 8.60%
2004 3.30%
2005 12.30%
2006 5.50%
2007 18.30%
2008 7.80%
2009 5.50%
2010 17.60%
2011 10.70%
2012 11.60%
2013 16.00%

*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.