VIENNA, MARYLAND

Monthly Average Temperature (Degrees Fahrenheit)

(189140)

File last updated on May 16,
*** Note *** Provisional Data *** After Year/Month 201005
a = 1 day missing, b = 2 days missing, c = 3 days, ..etc..,
z = 26 or more days missing, A = Accumulations present
Long-term means based on columns; thus, the monthly row may not
sum (or average) to the long-term annual value.
MAXIMUM ALLOWABLE NUMBER OF MISSING DAYS : 5
Individual Months not used for annual or monthly statistics if more than 5 days are missing.
Individual Years not used for annual statistics if any month in that year has more than 5 days missing.
YEAR(S) JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN
1949 ----- z ----- z ----- z ----- z ----- z ----- z 80.05 a 76.65 67.30 63.96 c 48.68 b 42.77 i 67.33
1950 48.18 c 39.02 d 42.55 51.77 63.19 72.43 76.34 74.23 66.73 60.50 48.55 36.34 56.65
1951 40.21 39.41 45.78 b 54.83 63.23 a 72.65 77.56 75.03 a 67.56 c 61.92 47.04 c 41.74 57.25
1952 40.58 40.02 45.03 56.87 63.81 74.98 78.97 75.94 68.07 54.82 48.32 38.98 57.20
1953 42.66 42.09 46.69 55.23 68.08 71.20 77.73 75.66 69.40 60.06 48.27 42.16 58.27
1954 36.81 43.23 45.94 57.48 62.77 73.25 77.18 75.10 71.68 63.61 c 47.43 a 38.74 57.77
1955 36.59 c 37.83 d 47.65 a 57.50 65.44 69.37 79.97 b 78.13 a 68.97 59.33 b 47.07 34.45 56.86
1956 34.40 42.12 44.16 52.60 62.61 73.30 76.94 75.76 68.23 60.48 49.41 a 46.74 57.23
1957 33.77 42.07 44.87 59.58 66.19 76.92 77.61 74.62 a 72.00 55.08 50.75 42.71 58.01
1958 34.13 32.66 41.65 56.10 64.21 70.85 79.32 75.52 68.15 58.89 50.62 31.23 55.28
1959 35.56 39.09 46.16 57.68 68.30 a 75.09 a 77.79 78.52 72.02 a 62.21 48.90 a 42.29 58.63
1960 38.97 39.59 a 34.79 59.88 63.45 73.40 75.52 77.53 70.55 58.47 50.23 33.13 56.29
1961 31.50 40.23 48.29 52.02 61.74 72.28 78.18 76.35 74.42 59.34 50.87 37.53 56.90
1962 35.87 35.80 43.31 55.13 67.21 72.62 73.90 74.79 66.93 59.76 45.88 33.89 55.42
1963 32.87 31.50 48.58 55.82 63.31 72.63 76.90 74.61 65.57 60.16 50.83 33.11 55.49
1964 37.56 36.74 47.16 53.68 66.14 b 73.02 76.77 73.40 a 68.75 54.94 50.13 42.27 56.71
1965 38.83 k 37.39 42.16 51.22 64.74 l 71.80 76.84 75.65 71.52 56.81 48.52 41.69 57.36
1966 33.10 36.54 46.55 51.57 63.32 72.77 77.87 76.53 67.68 57.23 49.50 37.85 55.88
1967 40.82 34.43 44.13 54.82 59.34 71.85 76.19 74.73 67.22 58.40 45.22 40.63 55.65
1968 32.31 33.64 48.47 56.60 63.55 74.83 79.06 78.34 70.07 61.97 51.43 37.31 57.30
1969 34.16 36.62 42.55 ----- z 66.31 76.17 78.65 75.50 o 70.35 58.73 48.50 a 37.34 54.94
1970 30.13 38.09 42.71 54.90 67.71 74.65 78.19 78.18 74.00 62.92 50.53 39.94 57.66
1971 32.61 39.62 44.39 54.55 63.89 75.30 77.26 75.23 72.97 65.71 49.63 c 48.10 58.27
1972 39.68 36.83 45.71 52.98 63.69 70.72 78.26 76.26 69.57 56.21 46.50 44.98 56.78
1973 38.21 36.64 51.11 55.97 63.52 76.38 77.81 77.85 71.95 60.97 50.17 40.84 58.45
1974 41.52 37.82 46.92 a 55.27 b 63.23 68.27 74.93 a 75.02 a 64.81 i 52.00 a 45.94 c 40.74 d 54.70
1975 40.50 r 40.85 a 44.45 52.24 a 67.37 75.17 c 76.91 c 79.47 b 67.88 59.84 53.60 40.90 59.88
1976 34.17 a 46.12 a 50.09 b 58.83 65.00 75.31 a 76.53 73.83 d 69.97 l 54.94 42.87 d 36.05 a 55.79
1977 26.57 a 38.12 b 51.76 60.44 f 66.95 71.66 a 79.48 c 78.68 72.59 a 56.98 d 51.60 39.03 57.58
1978 33.06 28.55 42.98 55.86 a 62.66 73.65 76.03 79.82 69.93 58.32 51.45 41.97 a 56.19
1979 36.05 26.57 49.95 54.77 67.32 70.60 76.84 76.81 70.88 e 58.09 c 52.75 b 41.70 f 58.24
1980 35.60 f 32.81 ----- z 57.86 i 62.61 m ----- z ----- z ----- z 72.94 n 57.93 c 47.05 38.52 c 44.08
1981 30.05 a 41.19 b 43.45 c 59.19 f 64.02 c 76.07 b 77.48 d 73.88 a 68.71 d 55.96 d 48.28 37.68 56.07
1982 29.40 38.66 46.11 53.55 67.77 72.08 78.77 73.53 68.92 58.94 51.43 45.02 b 57.02
1983 37.42 37.55 48.82 54.13 63.95 74.45 79.89 77.71 69.93 a 60.48 50.55 38.03 57.74
1984 31.53 44.67 41.95 54.88 65.08 75.57 75.56 76.73 68.35 65.37 47.20 47.40 57.86
1985 32.17 a 38.80 50.26 61.08 67.29 71.12 b 76.97 75.95 71.42 63.89 57.30 37.66 58.66
1986 36.69 37.59 47.90 a 56.57 69.48 75.62 81.82 75.55 70.43 62.71 48.88 41.53 58.73
1987 35.15 35.96 48.37 55.42 68.39 77.05 a 81.39 78.21 71.85 54.42 ----- z 43.06 d 59.02
1988 31.58 39.09 48.03 55.08 d 65.73 74.65 ----- z 79.84 c 67.88 53.30 a 48.85 38.44 54.77
1989 39.69 38.02 44.58 54.50 64.90 76.80 77.56 76.02 a 70.22 60.84 47.28 26.24 56.39
1990 41.95 44.29 b 48.73 56.82 b 63.68 73.80 78.29 74.66 ----- z 60.84 49.42 43.03 57.77
1991 36.98 40.15 a 47.13 54.22 65.95 73.85 77.63 75.13 67.27 58.40 48.07 43.44 57.35
1992 40.50 41.05 44.84 54.77 ----- z ----- z 79.82 74.55 70.33 56.24 50.55 a 40.81 55.35
1993 ----- z 34.64 41.89 54.57 a 65.33 j 74.18 81.90 77.98 71.20 58.02 48.32 37.48 58.02
1994 31.90 36.70 45.77 60.77 62.23 76.43 80.82 74.81 69.13 57.37 53.30 44.15 57.78
1995 40.06 35.07 48.37 56.58 64.35 73.65 80.11 78.24 69.92 62.27 44.78 38.55 t 59.40
1996 33.71 36.67 40.81 55.83 64.15 75.08 77.32 75.79 70.87 59.60 45.03 43.74 56.55
1997 37.89 43.12 48.89 53.65 62.63 71.43 79.29 75.06 70.22 59.39 47.57 40.82 57.50
1998 44.29 43.61 48.23 58.13 67.61 74.57 78.48 78.27 74.28 59.89 49.82 44.73 60.16
1999 41.98 a 40.04 a 44.34 b 56.62 a 66.47 72.97 81.28 a 77.60 a 70.15 c 58.79 n 55.10 d 44.07 d 59.15
2000 36.05 39.96 c 51.78 a 55.67 67.87 a 75.07 75.75 a 76.42 68.62 59.77 c 48.20 b 32.35 a 57.29
2001 36.26 42.30 44.23 a 56.26 c 63.50 e 75.60 75.64 b 77.91 b 69.52 a 60.00 k 54.07 b 45.91 b 58.29
2002 41.58 43.45 49.44 59.80 65.50 76.08 81.03 80.31 71.78 60.13 48.62 38.61 59.69
2003 32.32 i ----- z 49.87 56.23 b 61.94 72.92 79.85 78.56 71.91 g 59.76 d 55.25 40.21 61.62
2004 32.94 d 39.10 c 48.92 56.93 72.81 73.75 f 79.87 e 75.97 71.37 58.61 50.78 41.60 57.17
2005 37.37 39.18 42.37 56.15 61.40 74.83 80.18 79.34 73.23 61.76 52.02 38.63 58.04
2006 44.55 39.55 46.45 59.10 65.15 74.25 79.87 79.18 c 68.72 58.31 52.38 45.60 59.43
2007 42.44 30.98 b 48.59 b 54.69 a 66.74 75.05 77.81 78.80 f 72.33 66.73 48.45 41.84 56.88
2008 39.33 a 41.39 b 49.08 57.97 62.68 77.55 79.58 g 74.89 71.77 58.58 46.98 41.98 56.56
2009 33.52 40.29 44.69 b 58.67 d 66.45 73.27 76.92 ----- z 68.17 ----- z ----- z ----- z 57.75
2010 ----- z 33.25 ----- z ----- z 69.77 ----- z ----- z ----- z ----- z ----- z ----- z ----- z 51.51
Period of Record Statistics
MEAN 36.53 38.31 46.11 55.79 65.11 73.81 78.15 76.50 69.99 59.35 49.44 40.09 57.38
S.D. 4.39 3.85 3.17 2.29 2.46 2.02 1.80 1.80 2.04 3.02 2.72 4.24 1.16
SKEW 0.25 -0.66 -0.66 0.22 0.51 -0.43 0.18 0.34 0.20 0.07 0.40 -0.69 0.29
MAX 48.18 46.12 51.78 61.08 72.81 77.55 81.90 80.31 74.42 66.73 57.30 48.10 60.16
MIN 26.57 26.57 34.79 51.22 59.34 68.27 73.90 73.40 65.57 52.00 42.87 26.24 55.28
NO YRS 55 60 59 56 57 57 58 57 56 58 59 57 38