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 8.70%
1911 15.40%
1912 11.80%
1913 8.00%
1914 16.70%
1915 13.00%
1916 10.30%
1917 4.60%
1918 7.90%
1919 12.40%
1920 8.60%
1921 11.10%
1922 9.40%
1923 12.70%
1924 8.20%
1925 5.00%
1926 9.70%
1927 10.10%
1928 6.70%
1929 7.90%
1930 5.40%
1931 6.20%
1932 7.30%
1933 13.50%
1934 6.60%
1935 7.50%
1936 11.10%
1937 11.60%
1938 12.50%
1939 5.60%
1940 6.10%
1941 9.50%
1942 9.00%
1943 7.40%
1944 6.70%
1945 5.70%
1946 8.90%
1947 7.10%
1948 9.70%
1949 5.20%
1950 11.00%
1951 9.70%
1952 8.30%
1953 10.70%
1954 10.30%
1955 11.80%
1956 5.10%
1957 7.90%
1958 6.60%
1959 9.90%
1960 7.00%
1961 10.30%
1962 9.60%
1963 4.30%
1964 13.10%
1965 10.90%
1966 12.90%
1967 7.40%
1968 8.50%
1969 8.80%
1970 9.40%
1971 7.10%
1972 9.10%
1973 9.70%
1974 9.50%
1975 7.00%
1976 5.50%
1977 9.80%
1978 6.90%
1979 8.60%
1980 13.10%
1981 12.30%
1982 12.60%
1983 10.90%
1984 8.40%
1985 9.80%
1986 13.50%
1987 9.50%
1988 8.30%
1989 8.60%
1990 15.20%
1991 12.20%
1992 5.50%
1993 11.90%
1994 11.30%
1995 17.20%
1996 19.60%
1997 12.20%
1998 21.00%
1999 14.80%
2000 9.00%
2001 11.00%
2002 13.20%
2003 9.50%
2004 12.60%
2005 20.40%
2006 15.20%
2007 19.90%
2008 20.80%
2009 11.10%
2010 21.10%
2011 14.60%
2012 12.50%
2013 16.30%
2014 15.30%

*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.