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 2.10%
1911 8.60%
1912 13.40%
1913 10.50%
1914 12.70%
1915 2.20%
1916 2.20%
1917 10.40%
1918 10.40%
1919 9.20%
1920 6.40%
1921 9.90%
1922 2.00%
1923 10.20%
1924 10.30%
1925 10.20%
1926 20.70%
1927 2.00%
1928 8.10%
1929 2.10%
1930 7.90%
1931 11.40%
1932 5.90%
1933 10.30%
1934 2.00%
1935 10.30%
1936 14.00%
1937 17.90%
1938 2.00%
1939 2.00%
1940 17.20%
1941 8.00%
1942 10.50%
1943 14.80%
1944 1.90%
1945 2.00%
1946 10.00%
1947 14.70%
1948 4.10%
1949 16.10%
1950 8.20%
1951 8.00%
1952 19.50%
1953 24.70%
1954 9.60%
1955 6.10%
1956 9.50%
1957 11.50%
1958 11.80%
1959 17.50%
1960 3.70%
1961 7.70%
1962 6.10%
1963 11.80%
1964 6.00%
1965 2.10%
1966 9.70%
1967 12.10%
1968 20.60%
1969 9.70%
1970 5.80%
1971 3.80%
1972 9.40%
1973 4.00%
1974 6.30%
1975 7.80%
1976 11.40%
1977 4.00%
1978 17.20%
1979 9.80%
1980 8.30%
1981 6.00%
1982 12.10%
1983 27.50%
1984 11.40%
1985 8.30%
1986 5.80%
1987 10.20%
1988 11.90%
1989 4.00%
1990 10.10%
1991 17.10%
1992 4.10%
1993 12.10%
1994 14.10%
1995 5.90%
1996 15.50%
1997 2.10%
1998 7.60%
1999 13.90%
2000 21.60%
2001 2.00%
2002 19.00%
2003 1.90%
2004 6.00%
2005 5.70%
2006 7.70%
2007 25.00%
2008 20.30%
2009 2.20%
2010 28.40%
2011 9.80%
2012 10.80%
2013 22.60%

*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.