Casey 00Z 500hPa temperature 1957 - - - -32.3 -35.2 -34.3 -36.7 -37.1 -37.8 -34.1 -33.8 -29.7 1958 -29.1 -33.1 -33.5 -35.9 -33.5 -36.6 -36.7 -39.3 -40.1 -37.7 -35.4 -31.8 1959 -31.3 -30.3 -29.6 -32.5 -35.7 -37.1 -39.8 -37.2 -40.7 -35.3 -35.9 -29.9 1960 -29.9 -30.4 -35.7 -36.3 -36.2 -38.2 -39.5 -38.5 -39.0 -36.9 -34.2 -31.2 1961 -29.8 -28.4 -34.0 -33.8 -34.9 -34.8 -39.1 -36.9 -35.5 -34.3 -33.0 -34.8 1962 -32.6 -31.7 -34.7 -34.9 -37.2 -37.1 -39.6 -38.1 -38.6 -36.8 -33.1 -33.2 1963 -28.5 -32.9 -33.5 -36.0 -34.5 -38.6 -38.0 -35.4 -38.8 -37.6 -34.7 -30.4 1964 -30.1 -30.3 -33.1 -34.3 -36.6 -34.8 -34.7 -36.0 -38.7 -36.8 -33.0 -28.9 1965 -30.3 -30.5 -33.9 -34.2 -37.0 -39.8 -39.0 -39.0 -40.2 -38.8 -34.5 -28.6 1966 -30.8 -29.4 -32.0 -36.4 -34.6 -37.9 -34.9 -41.5 -37.0 -37.1 -33.4 -29.5 1967 -26.7 -32.0 -33.5 -34.8 - -36.4 -35.9 -38.6 -38.6 -38.9 -31.4 -30.7 1968 -29.8 -32.3 -33.2 -35.1 -35.8 -36.3 -37.5 -40.5 -39.7 -36.4 -33.5 -32.1 1969 -29.8 -32.6 - -37.5 -37.8 -36.7 -39.6 -40.1 -38.2 -35.8 -34.8 -31.5 1970 -29.0 -32.1 -31.0 -31.7 -32.8 -33.5 -36.9 -38.4 -36.5 -37.5 -33.8 -29.7 1971 -28.0 -29.3 -35.9 -34.4 -35.3 -38.7 -38.5 -37.6 -35.7 -36.5 -32.7 -29.2 1972 -28.8 -32.2 -34.1 -35.2 -38.1 -36.6 -38.5 -35.7 -39.8 -36.6 -34.7 -29.8 1973 -30.0 -33.1 -33.0 -34.4 -32.3 -34.4 -38.8 -39.7 -35.3 -35.9 -32.7 -31.9 1974 -29.7 -29.7 -35.4 -35.9 -38.6 -36.3 -38.6 -36.6 -39.5 -34.1 -33.3 -30.0 1975 -29.4 -30.5 -31.1 -36.4 -34.4 -36.0 -35.5 -40.2 -40.0 -35.7 -34.3 -31.3 1976 -28.6 -30.9 -32.4 -35.8 -36.4 -36.3 -38.7 -38.5 -38.0 -37.1 -33.2 -28.7 1977 -28.0 -29.2 -32.7 -36.6 -36.2 -36.6 -38.1 -37.7 -40.7 -37.6 -33.3 -30.6 1978 -31.4 -31.1 -32.4 -35.1 -34.7 -36.3 -38.3 -39.4 -39.4 -37.4 -32.2 -28.4 1979 -30.2 -30.5 -34.2 -34.0 -36.1 -38.2 -37.3 -39.0 -39.0 -35.0 -31.1 -29.5 1980 -29.3 -32.5 -33.2 -32.4 -36.4 -37.2 -34.8 -35.9 -35.9 -37.3 -32.6 -31.8 1981 -30.8 -30.3 -32.5 -36.2 -37.3 -35.7 -36.8 -34.8 -36.5 -37.5 -33.3 -30.5 1982 -29.9 -30.5 -34.4 -38.4 -36.1 -36.5 -34.9 -40.2 -39.4 -36.3 -32.5 -28.2 1983 -29.8 -31.3 -32.2 -34.5 -34.0 -35.6 -38.7 -36.9 -37.1 -37.0 -35.3 -31.0 1984 -28.0 -32.4 -32.3 -32.2 -33.7 -39.0 -38.0 -37.0 -38.5 -38.1 -32.0 -28.1 1985 -27.3 -30.7 -32.8 -33.5 -36.5 -35.0 -39.4 -37.9 -39.4 -37.8 -35.3 -31.0 1986 -30.0 -26.9 -31.9 -34.3 -33.6 -37.2 -36.9 -39.3 -37.1 -36.9 -33.9 -30.9 1987 -27.8 -29.5 -30.6 -35.5 -37.1 -36.7 -37.1 -39.0 -39.2 -37.0 -34.0 -31.0 1988 -27.5 -31.9 -31.3 -33.3 -32.5 -33.7 -36.4 -36.7 -34.5 -35.3 -33.8 -32.2 1989 -29.9 -31.4 -33.5 -33.8 -37.6 -36.9 -36.6 -36.9 -35.9 -34.6 -34.3 -25.7 1990 -28.2 -29.7 -31.1 -31.2 -33.8 -37.4 -34.3 -38.5 -39.3 -36.4 -32.8 -28.3 1991 -32.2 -29.6 -29.9 -32.6 -35.8 -33.4 -32.5 -36.1 -39.2 -37.2 -31.3 -30.5 1992 -28.8 -30.3 -30.9 -36.7 -33.6 -32.4 -36.6 -37.3 -40.3 -36.4 -33.4 -32.0 1993 -29.6 -30.9 -31.2 -36.7 -38.2 -38.0 -37.0 -38.7 -37.6 -37.0 -35.7 -33.2 1994 -29.2 -31.9 -33.6 -36.4 -35.1 -32.8 -36.2 -38.4 -35.8 -37.9 -33.1 -33.6 1995 -30.8 -31.4 -32.1 -34.4 -35.6 -35.9 -31.2 -36.0 -38.3 -36.9 -32.0 -29.8 1996 -29.1 -30.2 -33.2 -32.9 -37.8 -32.8 -35.1 -33.9 -35.1 -35.9 -33.7 -31.6 1997 -30.9 -31.6 -31.9 -35.3 -34.0 -35.2 -39.7 -38.9 -39.3 -36.9 -32.3 -30.0 1998 -31.0 -29.5 -33.0 -35.3 -38.3 -36.4 -37.4 -35.2 -36.2 -37.7 -32.2 -33.7 1999 -32.2 -29.8 -32.4 -37.0 -37.1 -35.7 -38.2 -38.7 -38.0 -36.6 -33.4 -32.0 2000 -29.9 -31.2 -33.1 -31.8 -36.8 -34.3 -36.7 -38.3 -35.5 -37.9 -30.6 -30.0 2001 -28.4 -26.6 -31.4 -36.3 -34.9 -36.1 -36.5 -40.1 -38.2 -36.3 -33.6 -28.6 2002 -31.3 -30.8 -29.0 -33.4 -30.9 -33.8 -35.3 -37.6 -37.2 -33.9 -34.0 -29.2 2003 -27.9 -25.7 -31.2 -34.8 -35.7 -35.3 -37.3 -37.0 -36.6 -37.7 -31.6 -29.4 2004 -27.7 -31.1 -32.7 -36.3 -34.7 -35.9 -39.4 -37.2 -40.5 -35.5 -32.3 -29.5 2005 -29.6 -30.8 -30.9 -37.8 -32.7 -34.5 -36.1 -38.2 -35.7 -35.8 -34.0 -27.9 2006 -30.4 -32.0 -32.7 -33.3 -39.6 -37.8 -37.3 -37.1 -36.3 -36.8 -33.2 -31.6 2007 -28.3 -31.0 -33.2 -31.9 -31.4 -34.0 -34.5 -35.3 -36.7 -36.1 -31.9 -32.7 2008 -31.7 -30.1 -33.3 -33.0 -34.1 -38.7 -37.9 -38.7 -38.8 -37.8 -31.8 -30.1 2009 -30.4 -29.7 -31.7 -33.8 -36.0 -36.8 -33.0 -37.7 -36.2 -37.2 -33.4 -32.2 2010 -28.7 -29.7 -30.8 -34.4 -37.3 -36.9 -38.8 -38.9 -35.6 -36.8 -34.0 -29.1 2011 -27.9 -33.7 -31.0 -33.3 -35.4 -36.9 -32.8 -36.1 -34.6 -38.9 -33.9 -34.0 2012 -30.2 -31.8 -33.2 -32.6 -36.7 -36.2 -40.2 -38.5 -39.1 -35.1 -32.2 -31.3 2013 -29.1 -29.7 -34.0 -35.5 -34.9 -35.3 -37.3 -37.6 -31.7 -36.3 -30.1 -31.5 2014 -28.8 -30.2 -32.0 -36.8 -34.3 -36.8 -37.6 -39.4 -36.5 -36.2 -30.9 -32.3 2015 -29.2 -32.1 -33.1 -35.4 -36.9 -35.3 -38.1 -37.1 -38.4 -38.7 -32.2 -30.6 2016 -30.7 -33.6 -32.5 -33.9 -33.9 -37.7 -37.0 -38.3 -38.7 -35.4 -33.3 -31.1 2017 -29.3 -29.1 -33.4 -35.2 -33.9 -37.3 -35.7 -39.0 -38.2 -36.6 -33.3 -30.6 2018 -30.3 -29.9 -33.5 -32.0 -37.5 -36.2 -35.6 -37.2 -38.9 -38.5 -35.2 -32.4 2019 -31.1 -29.4 -33.0 -33.2 -35.6 -35.8 -34.9 -36.0 -38.0 -35.4 -31.5 -29.3 2020 -28.0 -30.6 -33.4 -31.5 -33.9 -36.9 -33.3 -35.6 -34.9 -34.1 -32.5 -31.6 2021 -31.9 -30.8 -31.7 -33.7 -36.1 -39.1 -37.2 -35.7 -36.9 -34.0 -35.8 -28.7 2022 -32.1 -30.8 -34.1 -34.9 -34.1 -32.2 -36.5 -35.6 -37.0 -35.7 -34.4 -31.7 2023 -31.7 -29.1 -30.1 -34.5 -37.0 -35.5 -38.2 -39.9 -35.3 -37.2 -34.0 -29.7 2024 -30.2 -32.2 -33.0 -34.5 - - - - - - - -