Average Temperatures for December at Boise, Idaho (airport) for the 72-year period 1940 through 2011 normal (1981-10) = 30.7 F degrees RANK RANK AMONG AMONG DATA YEAR COLDEST WARMEST 12.6 1985 1 72 18.1 1990 w+ 2 71 22.9 1984 3 70 23.2 1983 w+ 4 69 23.8 1972 c- 5 68 25.4 1948 6 67 26.7 2009 w 7 66 27.0 1978 w+ 8 tie 27.0 1988 w- tie 64 27.5 1951 c+ 10 63 27.8 1967 c+ 11 62 27.9 1959 w+ 12 61 28.0 1986 13 60 28.1 1963 c 14 59 28.5 1992 w+ 15 58 29.0 1944 w- 16 57 29.3 1976 c+ 17 56 29.5 2005 c- 18 55 30.1 1965 19 54 30.2 1971 c+ 20 53 30.4 1989 c+ 21 52 30.4 1994 22 51 30.5 1960 c- 23 50 30.6 1954 24 49 30.7 1956 c+ 25 tie 30.7 1998 tie tie 30.7 2001 tie 46 30.8 1945 c- 28 45 30.9 1961 29 44 31.1 1949 w- 30 tie 31.1 2000 tie 42 31.2 1997 w+ 32 41 31.3 1953 w 33 tie 31.3 1966 w tie tie 31.3 2011 c- tie 38 31.4 1947 w 36 tie 31.4 1975 tie 36 31.5 1982 c 38 tie 31.5 2008 tie 34 31.7 1991 40 33 31.8 2006 w 41 32 31.9 1999 c+ 42 31 32.4 2007 c+ 43 30 32.8 1943 c+ 44 29 32.9 1987 w+ 45 28 33.1 1980 46 tie 33.1 1995 w tie 26 33.2 1974 c+ 48 25 33.3 1993 w+ 49 24 33.4 1942 w+ 50 23 33.5 1970 w 51 22 34.1 1952 w+ 52 21 34.4 1957 c- 53 20 34.6 1969 w+ 54 19 35.0 1941 w+ 55 tie 35.0 2010 c+ tie 17 35.1 1968 c- 57 16 35.2 1964 w 58 15 35.3 1940 w 59 tie 35.3 1981 tie 13 35.4 1955 c 61 tie 35.4 1962 c+ tie tie 35.4 2004 w- tie 10 35.8 1979 64 9 36.2 1946 65 8 36.3 1950 c+ 66 tie 36.3 1996 tie 6 36.6 1958 w+ 68 5 37.2 2003 69 4 37.3 1977 w- 70 3 37.3 2002 w 71 2 38.4 1973 w+ 72 1 1/4/2012 c = la nina w = el nino weak c- or w- moderate c or w strong c+ or w+ average december temperatures at boise, airport.txt