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 5.50%
1911 3.40%
1912 5.80%
1913 12.50%
1914 3.60%
1915 6.00%
1916 11.30%
1917 5.70%
1918 8.80%
1919 10.40%
1920 12.20%
1921 3.40%
1922 15.40%
1923 12.00%
1924 10.10%
1925 7.40%
1926 5.30%
1927 10.10%
1928 5.30%
1929 12.20%
1930 7.00%
1931 12.10%
1932 10.30%
1933 18.30%
1934 18.30%
1935 8.40%
1936 12.10%
1937 11.70%
1938 15.00%
1939 5.00%
1940 5.00%
1941 6.70%
1942 6.90%
1943 13.20%
1944 6.80%
1945 3.60%
1946 19.00%
1947 6.90%
1948 3.50%
1949 6.80%
1950 6.60%
1951 7.40%
1952 6.60%
1953 5.10%
1954 5.00%
1955 10.10%
1956 5.10%
1957 15.10%
1958 20.50%
1959 3.40%
1960 12.00%
1961 8.30%
1962 3.40%
1963 5.00%
1964 13.70%
1965 10.10%
1966 10.30%
1967 5.00%
1968 10.60%
1969 15.00%
1970 10.20%
1971 3.40%
1972 5.00%
1973 15.80%
1974 5.10%
1975 1.80%
1976 9.00%
1977 8.40%
1978 3.40%
1979 10.10%
1980 10.20%
1981 16.40%
1982 5.30%
1983 10.10%
1984 10.20%
1985 8.50%
1986 5.30%
1987 10.10%
1988 15.30%
1989 10.30%
1990 10.00%
1991 10.30%
1992 14.30%
1993 12.50%
1994 6.90%
1995 8.70%
1996 7.00%
1997 7.00%
1998 17.40%
1999 10.10%
2000 13.70%
2001 5.80%
2002 13.30%
2003 6.80%
2004 3.40%
2005 12.60%
2006 14.80%
2007 30.00%
2008 14.50%
2009 9.50%
2010 16.20%
2011 14.50%
2012 6.10%
2013 15.80%
2014 16.60%

*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.