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 9.60%
1911 7.70%
1912 9.70%
1913 13.10%
1914 12.40%
1915 8.60%
1916 9.90%
1917 3.70%
1918 13.00%
1919 6.40%
1920 8.90%
1921 7.90%
1922 9.90%
1923 9.20%
1924 1.70%
1925 7.60%
1926 8.50%
1927 9.00%
1928 9.20%
1929 12.90%
1930 7.30%
1931 5.70%
1932 5.10%
1933 9.00%
1934 8.60%
1935 6.40%
1936 9.20%
1937 5.90%
1938 9.80%
1939 8.90%
1940 7.90%
1941 6.80%
1942 12.30%
1943 9.50%
1944 7.30%
1945 8.40%
1946 5.20%
1947 4.20%
1948 8.60%
1949 3.80%
1950 7.20%
1951 8.50%
1952 9.10%
1953 6.60%
1954 7.60%
1955 10.50%
1956 8.00%
1957 9.00%
1958 5.00%
1959 5.20%
1960 6.40%
1961 5.60%
1962 8.40%
1963 5.00%
1964 16.40%
1965 4.90%
1966 7.10%
1967 7.90%
1968 5.90%
1969 10.20%
1970 10.00%
1971 8.20%
1972 9.80%
1973 11.80%
1974 8.20%
1975 5.70%
1976 7.20%
1977 9.80%
1978 8.10%
1979 7.10%
1980 8.10%
1981 5.10%
1982 4.80%
1983 9.30%
1984 7.30%
1985 8.40%
1986 9.80%
1987 11.20%
1988 10.00%
1989 8.00%
1990 9.40%
1991 15.20%
1992 7.30%
1993 7.40%
1994 7.50%
1995 12.00%
1996 13.50%
1997 6.70%
1998 11.00%
1999 9.50%
2000 13.60%
2001 11.50%
2002 9.20%
2003 9.40%
2004 12.50%
2005 11.00%
2006 7.70%
2007 14.20%
2008 15.10%
2009 14.00%
2010 12.50%
2011 18.40%
2012 11.50%
2013 18.70%

*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.