(1) The year listed is for the December of that year. For 1950 for instance, it is the winter of 1950-1951.
(2) NAO data goes back to 1950.
(3) Philadelphia average temperature and snowfall is 34.8 degrees and 20.2 inches of snow between 1971 and 2000.
(4) Average December temperature is 37.4 degrees. Average January temperature is 32.9 degrees. Average February temperature is 35.7 degrees.
| Year | DEC | TEMP | JAN | TEMP | FEB | TEMP | WINTER NAO | WINTER TEMP | Winter Snow |
| 1950 | -1.02 | 34.2 | 0.08 | 36.0 | 0.70 | 36.4 | -0.08 | 35.5 | 4.6 |
| 1951 | 1.32 | 38.7 | 0.93 | 37.3 | -0.83 | 38.2 | 0.47 | 38.1 | 16.2 |
| 1952 | -0.43 | 38.5 | 0.33 | 38.0 | -0.49 | 38.9 | -0.20 | 38.5 | 16.8 |
| 1953 | -0.47 | 39.4 | 0.37 | 31.7 | 0.74 | 41.2 | 0.21 | 37.4 | 22.6 |
| 1954 | 0.69 | 36.0 | -1.84 | 32.6 | -1.12 | 36.1 | -0.76 | 34.9 | 12.1 |
| 1955 | 0.17 | 30.5 | -0.22 | 32.1 | -1.12 | 37.6 | -0.39 | 33.4 | 23.0 |
| 1956 | 0.10 | 41.7 | 1.05 | 29.2 | 0.11 | 37.4 | 0.42 | 36.1 | 7.9 |
| 1957 | 0.12 | 39.4 | -0.54 | 31.8 | -1.06 | 28.2 | -0.49 | 33.1 | 41.8 |
| 1958 | -0.70 | 29.4 | -0.87 | 31.6 | 0.68 | 33.3 | -0.30 | 31.4 | 5.1 |
| 1959 | 0.44 | 38.2 | -1.29 | 34.2 | -1.89 | 35.4 | -0.91 | 35.9 | 21.8 |
| 1960 | 0.06 | 27.6 | 0.41 | 25.0 | 0.45 | 34.0 | 0.31 | 28.9 | 49.1 |
| 1961 | -1.48 | 31.0 | 0.61 | 30.0 | 0.55 | 30.4 | -0.11 | 30.5 | 29.2 |
| 1962 | -1.32 | 31.0 | -2.12 | 27.5 | -0.96 | 26.5 | -1.47 | 28.3 | 20.5 |
| 1963 | -1.92 | 27.9 | -0.95 | 33.0 | -1.43 | 31.8 | -1.43 | 30.9 | 32.9 |
| 1964 | -0.15 | 37.5 | -0.12 | 29.2 | -1.55 | 33.3 | -0.61 | 33.3 | 26.2 |
| 1965 | 1.37 | 37.0 | -1.74 | 29.1 | -1.39 | 31.5 | -0.59 | 32.5 | 27.4 |
| 1966 | 0.72 | 35.5 | -0.89 | 36.0 | 0.19 | 29.0 | 0.01 | 33.5 | 44.3 |
| 1967 | -0.45 | 38.5 | 0.13 | 28.9 | -1.29 | 30.4 | -0.54 | 32.6 | 15.9 |
| 1968 | -1.40 | 32.3 | -0.83 | 29.8 | -1.55 | 32.0 | -1.26 | 31.4 | 23.7 |
| 1969 | -0.28 | 33.5 | -1.50 | 24.5 | 0.64 | 33.1 | -0.38 | 30.4 | 20.3 |
| 1970 | -1.20 | 35.8 | -1.13 | 27.8 | 0.24 | 36.1 | -0.70 | 33.2 | 18.3 |
| 1971 | 0.60 | 41.6 | 0.27 | 35.1 | 0.32 | 32.4 | 0.40 | 36.4 | 12.2 |
| 1972 | 0.19 | 39.9 | 0.04 | 34.4 | 0.85 | 33.6 | 0.36 | 36.0 | 0.0 |
| 1973 | 0.32 | 38.6 | 1.34 | 35.9 | -0.14 | 31.7 | 0.51 | 35.4 | 20.8 |
| 1974 | 1.50 | 39.4 | 0.58 | 37.3 | -0.62 | 35.8 | 0.49 | 37.5 | 13.6 |
| 1975 | 0.00 | 36.9 | -0.25 | 28.7 | 0.93 | 40.9 | 0.23 | 35.5 | 17.5 |
| 1976 | -1.60 | 30.3 | -1.04 | 20.0 | -0.49 | 33.6 | -1.04 | 28.0 | 18.7 |
| 1977 | -1.00 | 32.6 | 0.66 | 28.0 | -2.20 | 24.7 | -0.85 | 28.4 | 54.9 |
| 1978 | -1.57 | 38.6 | -1.38 | 32.5 | -0.67 | 23.0 | -1.21 | 31.4 | 40.2 |
| 1979 | 1.00 | 38.2 | -0.75 | 31.8 | 0.05 | 29.7 | 0.10 | 33.2 | 20.9 |
| 1980 | 0.78 | 32.5 | 0.37 | 25.3 | 0.92 | 37.9 | 0.69 | 31.9 | 15.4 |
| 1981 | -0.02 | 34.6 | -0.89 | 24.7 | 1.15 | 34.4 | 0.08 | 31.2 | 25.4 |
| 1982 | 1.78 | 41.3 | 1.59 | 34.1 | -0.53 | 34.0 | 0.95 | 36.5 | 35.9 |
| 1983 | 0.29 | 33.2 | 1.66 | 26.2 | 0.72 | 38.7 | 0.89 | 32.7 | 21.6 |
| 1984 | 0.00 | 41.9 | -1.61 | 27.3 | -0.49 | 35.3 | -0.70 | 34.8 | 16.5 |
| 1985 | 0.22 | 33.3 | 1.11 | 32.8 | -1.00 | 32.1 | 0.11 | 32.7 | 16.4 |
| 1986 | 0.99 | 37.9 | -1.15 | 31.9 | -0.73 | 32.5 | -0.30 | 34.1 | 25.7 |
| 1987 | 0.32 | 39.2 | 1.02 | 27.3 | 0.76 | 34.6 | 0.70 | 33.7 | 15.0 |
| 1988 | 0.61 | 35.4 | 1.17 | 36.5 | 2.00 | 34.8 | 1.26 | 35.6 | 11.2 |
| 1989 | -1.15 | 25.5 | 1.04 | 40.3 | 1.41 | 41.2 | 0.43 | 35.7 | 17.0 |
| 1990 | 0.22 | 42.1 | 0.86 | 35.2 | 1.04 | 40.0 | 0.71 | 39.1 | 14.6 |
| 1991 | 0.46 | 39.6 | -0.13 | 35.7 | 1.07 | 37.5 | 0.47 | 37.6 | 4.7 |
| 1992 | 0.47 | 38.8 | 1.60 | 38.2 | 0.50 | 31.9 | 0.86 | 36.3 | 24.3 |
| 1993 | 1.56 | 38.4 | 1.04 | 27.4 | 0.46 | 33.2 | 1.02 | 33.0 | 23.1 |
| 1994 | 2.02 | 41.9 | 0.93 | 38.2 | 1.14 | 31.5 | 1.36 | 37.2 | 9.8 |
| 1995 | -1.67 | 31.6 | -0.12 | 30.2 | -0.07 | 33.9 | -0.62 | 31.9 | 65.5 |
| 1996 | -1.41 | 40.2 | -0.49 | 32.5 | 1.70 | 40.0 | -0.07 | 37.6 | 12.9 |
| 1997 | -0.96 | 38.5 | 0.39 | 41.0 | -0.11 | 41.8 | -0.23 | 40.4 | 0.8 |
| 1998 | 0.87 | 42.0 | 0.77 | 35.0 | 0.29 | 38.0 | 0.64 | 38.3 | 12.5 |
| 1999 | 1.61 | 39.9 | 0.60 | 32.1 | 1.70 | 37.5 | 1.30 | 36.5 | 21.0 |
| 2000 | -0.58 | 31.3 | 0.25 | 32.5 | 0.45 | 37.4 | 0.04 | 33.7 | 26.1 |
| 2001 | -0.83 | 43.7 | 0.44 | 39.2 | 1.10 | 41.1 | 0.24 | 41.3 | 4.0 |
| 2002 | -0.94 | 35.4 | 0.16 | 28.5 | 0.62 | 29.9 | -0.05 | 31.3 | 46.3 |
| 2003 | 0.64 | 36.8 | -0.29 | 26.1 | -0.14 | 35.4 | 0.07 | 32.8 | 18.0 |
| 2004 | 1.21 | 37.7 | 1.52 | 31.8 | -0.06 | 36.1 | 0.89 | 35.2 | 30.4 |
| 2005 | -0.44 | 34.4 | 1.26 | 40.7 | -0.51 | 35.6 | 0.10 | 36.9 | 19.5 |
| 2006 | 1.34 | 42.7 | 0.22 | 38.2 | -0.47 | 27.9 | 0.36 | 36.3 | 13.4 |
| 2007 | 0.34 | 37.6 | 0.89 | 35.9 | 0.73 | 36.9 | 0.65 | 36.8 | 6.0 |
| 2008 | -0.28 | 38.7 | -0.01 | 29.0 | 0.06 | 37.1 | -0.08 | 34.9 | 22.8 |
| 2009 | -1.93 | 36.4 | -1.11 | 33.2 | -1.98 | 31.8 | -1.67 | 33.8 | 78.7 |
| 2010 | -1.85 | 32.7 | -0.88 | 29.3 | 0.70 | 37.2 | -0.68 | 33.1 | 44.0 |
