YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
1937 | 2.90 | b | 16.39 | 26.45 | 29.40 | 33.13 | 41.20 | 50.97 | 47.68 | 45.87 | 34.17 | a | 28.30 | 27.19 | 31.97 | |||||||||||
1938 | 21.47 | a | 20.18 | 24.35 | 31.53 | 35.32 | 45.47 | 53.77 | 47.81 | 46.23 | 34.84 | 22.00 | 22.15 | k | 34.82 | a | ||||||||||
1939 | 20.15 | d | 17.64 | 26.67 | a | 31.77 | 38.87 | a | 38.00 | h | 51.94 | 50.58 | 42.69 | a | 33.17 | a | 25.24 | a | 24.87 | 33.05 | a | |||||
1940 | 20.16 | 25.07 | 29.23 | 31.17 | 38.45 | b | 45.29 | b | 50.63 | a | 50.45 | 43.59 | a | 36.71 | 24.47 | 23.65 | 34.90 | |||||||||
1941 | 21.00 | a | 23.68 | 28.26 | 31.86 | a | 38.17 | a | 40.83 | a | 50.06 | 47.32 | 38.43 | 33.16 | 28.73 | 22.35 | 33.66 | |||||||||
1942 | 12.97 | 16.57 | 22.58 | 30.50 | 33.77 | 39.87 | 50.26 | 49.23 | 41.83 | 33.74 | 24.90 | 21.19 | 31.45 | |||||||||||||
1943 | 13.13 | 20.30 | a | 22.32 | 32.70 | 32.16 | 36.83 | 46.19 | d | 43.00 | 42.07 | 31.90 | a | 23.70 | 18.43 | a | 30.23 | |||||||||
1944 | 8.10 | 16.52 | 19.68 | 25.77 | 31.39 | 37.07 | 43.13 | 41.16 | 38.47 | 33.97 | 18.93 | 14.16 | 27.36 | |||||||||||||
1945 | 16.29 | 20.25 | 19.84 | 23.73 | 34.29 | 36.41 | a | 46.94 | 46.00 | 39.30 | 35.68 | 22.80 | 18.06 | 29.97 | ||||||||||||
1946 | 14.77 | 16.18 | 25.52 | 29.00 | 34.48 | 40.03 | 50.10 | 53.29 | 39.09 | g | 27.40 | a | 24.43 | 22.77 | a | 30.72 | a | |||||||||
1947 | 9.71 | c | 23.46 | 26.39 | 29.86 | i | 40.35 | 36.70 | 45.88 | f | 44.67 | j | 36.87 | 33.87 | 24.45 | a | 19.55 | 27.93 | c | |||||||
1948 | 21.13 | a | 17.57 | a | 22.13 | 26.63 | 34.23 | 45.53 | 46.53 | a | 43.63 | a | 37.73 | 32.20 | a | 21.33 | 9.58 | 29.85 | ||||||||
1949 | 0.61 | 16.25 | 25.10 | 29.40 | 36.00 | a | 39.69 | d | 45.21 | b | 43.00 | a | 38.52 | a | 23.28 | b | 25.67 | 12.26 | 27.91 | |||||||
1950 | 5.97 | 13.70 | a | 19.30 | a | 23.96 | c | 29.13 | a | 37.30 | 49.29 | 49.53 | l | 38.40 | o | 36.12 | e | 27.45 | a | 26.70 | a | 26.89 | b | |||
1951 | 13.97 | 22.52 | a | 21.00 | 30.55 | a | 36.30 | a | 40.96 | d | 49.26 | d | 47.06 | 41.17 | a | 31.07 | a | 18.77 | 11.20 | a | 30.32 | |||||
1952 | 10.43 | a | 13.76 | 14.57 | j | 32.22 | g | 36.13 | 40.66 | a | 48.03 | 49.77 | 43.47 | 37.29 | 20.00 | a | 19.47 | a | 31.90 | b | ||||||
1953 | 28.28 | b | 24.00 | 24.23 | 27.40 | 32.10 | 37.03 | 48.42 | 47.06 | 45.40 | e | 33.25 | g | 29.80 | 21.03 | 33.16 | a | |||||||||
1954 | 19.70 | a | 24.85 | b | 20.90 | 29.47 | 36.53 | a | 38.10 | 48.94 | 45.10 | a | 38.59 | a | 31.37 | d | 28.73 | 15.37 | a | 31.47 | ||||||
1955 | 12.00 | 15.62 | b | 21.20 | a | 25.17 | 33.29 | c | 43.55 | a | 45.58 | 49.59 | b | 40.03 | a | 32.63 | a | 23.10 | 21.27 | a | 30.25 | |||||
1956 | 19.06 | 15.55 | 23.45 | b | 30.87 | 39.48 | b | 40.53 | 51.48 | 48.89 | c | 42.53 | 31.23 | a | 22.07 | c | 20.65 | 32.15 | ||||||||
1957 | 7.87 | a | 21.28 | c | 26.27 | a | 29.57 | 38.48 | 43.10 | 45.37 | a | 46.13 | 42.89 | c | 32.39 | c | 21.14 | b | 23.13 | 31.47 | ||||||
1958 | 19.90 | 27.61 | 22.10 | a | 28.40 | 41.00 | 44.97 | a | 51.39 | 52.52 | 38.83 | 33.87 | 24.27 | d | 24.45 | 34.11 | ||||||||||
1959 | 22.45 | 22.19 | a | 23.65 | 29.62 | a | 31.32 | 42.80 | 50.42 | 45.68 | 37.62 | a | 34.06 | 23.46 | b | 15.58 | e | 31.57 | ||||||||
1960 | 17.50 | g | 18.68 | a | 26.40 | a | 28.70 | 32.52 | 41.30 | 52.65 | 45.77 | 42.27 | 32.86 | b | 23.37 | 18.69 | b | 33.02 | a | |||||||
1961 | 20.77 | 27.41 | a | 25.63 | a | 27.85 | d | 31.55 | 47.70 | 52.00 | 53.10 | 36.27 | 32.77 | a | 20.77 | 18.67 | a | 32.87 | ||||||||
1962 | 11.70 | a | 21.25 | 23.35 | e | 32.33 | c | 33.77 | 41.83 | 48.19 | 47.24 | f | 43.43 | g | 33.00 | 27.10 | a | 23.54 | c | 29.61 | b | |||||
1963 | 14.95 | i | 29.48 | a | 24.55 | 26.90 | 37.68 | 40.60 | 44.35 | 47.48 | 46.93 | 35.52 | 26.52 | i | 22.03 | a | 35.55 | b | ||||||||
1964 | 16.50 | a | 17.93 | a | 20.47 | a | 25.57 | 31.45 | b | 40.70 | c | 48.76 | b | 43.97 | 38.03 | a | 34.57 | a | 24.79 | b | 21.55 | b | 30.36 | |||
1965 | 20.29 | 24.61 | 21.93 | a | 31.13 | 31.04 | c | 41.71 | b | 47.87 | a | 46.04 | c | 36.93 | a | 35.44 | f | 28.37 | 18.19 | e | 31.65 | a | ||||
1966 | 17.03 | b | 18.59 | a | 23.71 | g | 28.33 | c | 36.96 | c | 39.25 | n | 45.74 | 47.23 | 43.64 | b | 32.13 | a | 28.55 | a | 20.57 | c | 31.88 | b | ||
1967 | 21.43 | a | 23.14 | f | 23.00 | 24.59 | a | 35.87 | 43.48 | a | 52.58 | 52.83 | a | 44.56 | c | 30.93 | d | 29.14 | i | 16.81 | d | 34.61 | b | |||
1968 | 15.97 | a | 26.76 | 25.68 | 25.33 | 34.68 | 42.76 | a | 51.58 | 46.10 | 41.73 | 31.90 | 28.37 | 22.20 | a | 32.75 | ||||||||||
1969 | ----- | z | 20.36 | 24.30 | k | 29.83 | 39.48 | 45.87 | 48.03 | 45.94 | 43.00 | c | 29.48 | 24.67 | 22.70 | a | 34.94 | b | ||||||||
1970 | 22.13 | 24.26 | a | 21.55 | 23.40 | 34.97 | 45.57 | 49.68 | 50.71 | 35.10 | 29.06 | 26.97 | 13.10 | j | 33.04 | a | ||||||||||
1971 | 21.36 | f | 20.75 | 19.67 | a | 27.24 | a | 35.16 | 40.50 | 50.58 | 53.32 | 36.17 | 29.61 | 23.83 | 15.23 | a | 32.01 | a | ||||||||
1972 | 16.67 | a | 21.76 | 28.26 | 25.87 | 35.71 | 43.57 | b | 47.57 | a | 48.00 | 33.76 | a | 32.73 | a | 27.13 | 12.90 | 31.16 | ||||||||
1973 | 16.84 | 25.19 | a | 25.77 | a | 30.17 | 40.23 | a | 44.60 | 52.39 | 50.30 | a | 42.90 | 33.58 | 26.53 | 24.77 | 34.44 | |||||||||
1974 | 17.03 | 21.36 | 25.23 | 28.87 | 33.87 | 47.80 | 50.77 | 51.06 | 46.77 | 35.35 | 26.43 | 22.48 | b | 33.92 | ||||||||||||
1975 | 19.52 | d | 21.40 | h | 22.23 | r | 25.81 | d | 36.19 | d | 43.43 | 55.19 | e | 47.70 | a | 48.60 | 35.19 | 28.46 | d | 24.41 | i | 37.79 | c | |||
1976 | 25.92 | g | 21.54 | e | 24.42 | 28.21 | a | 38.14 | c | 40.77 | 52.48 | 48.61 | 45.73 | 36.00 | b | 31.10 | a | 22.74 | 35.43 | a | ||||||
1977 | 14.55 | 25.29 | 23.23 | 33.90 | 33.13 | a | 47.53 | 48.94 | 55.23 | 41.07 | 36.03 | 25.68 | b | 24.29 | 34.07 | |||||||||||
1978 | 21.19 | 23.14 | 31.48 | ----- | z | 33.55 | 43.20 | 51.97 | 49.84 | 40.28 | a | 36.61 | 21.33 | 14.97 | 33.41 | a | ||||||||||
1979 | 10.30 | a | 24.42 | b | 29.21 | g | 30.37 | 39.13 | 45.00 | 51.48 | 50.84 | 47.63 | 40.90 | 23.07 | 22.32 | 35.04 | a | |||||||||
1980 | 17.39 | 27.64 | a | 25.84 | 33.20 | 37.29 | 41.17 | a | 52.52 | 47.45 | 43.90 | 35.07 | a | 28.54 | d | 29.23 | e | 34.94 | ||||||||
1981 | 21.89 | l | 21.93 | 28.71 | 32.11 | b | 35.45 | b | 41.10 | 48.47 | a | 53.19 | 44.37 | 32.79 | c | 29.27 | d | 22.25 | k | 36.74 | b | |||||
1982 | 12.17 | y | ----- | z | 18.57 | x | 26.07 | p | 32.61 | m | 46.61 | b | 50.81 | e | 49.96 | f | 42.87 | g | 33.29 | j | 22.94 | l | 13.73 | t | 48.71 | j |
1983 | 19.54 | r | 23.80 | r | 28.27 | p | 27.11 | u | 40.82 | i | 42.74 | g | 46.11 | c | 53.33 | d | 40.33 | i | 36.32 | l | 25.53 | o | 18.76 | n | 49.72 | j |
1984 | 15.35 | n | 16.58 | q | 26.83 | s | 26.60 | o | 33.29 | q | 42.56 | l | 52.70 | k | 51.35 | n | 40.78 | u | 30.33 | y | 27.31 | q | 12.90 | 12.90 | k | |
1985 | 14.07 | b | 16.00 | 22.10 | 34.07 | a | 36.62 | g | 43.73 | o | 55.79 | g | 48.85 | e | 38.50 | p | 14.43 | q | 10.77 | q | 11.19 | j | 27.02 | g | ||
1986 | 21.74 | h | 26.59 | f | 31.40 | a | 27.61 | b | 35.24 | f | 49.50 | f | 46.21 | c | 53.79 | c | 35.96 | f | 37.21 | b | 29.33 | c | 21.19 | 35.25 | e | |
1987 | 16.20 | a | 24.54 | 27.87 | 33.52 | a | 39.55 | b | 46.54 | d | 45.88 | f | 49.76 | f | 47.39 | b | 39.90 | a | 25.50 | j | 20.46 | g | 34.44 | d | ||
1988 | 15.59 | d | 25.11 | b | 24.81 | e | 31.93 | a | 34.48 | b | 44.04 | b | 51.03 | b | 49.77 | 42.07 | c | 43.35 | e | 26.40 | 18.00 | a | 33.88 | |||
1989 | 15.93 | b | 13.16 | c | 27.74 | 34.60 | 37.00 | a | 46.12 | d | 49.39 | 47.00 | e | 44.46 | b | 35.10 | a | 27.66 | a | 21.90 | 33.34 | |||||
1990 | 23.48 | 18.21 | 28.48 | b | 36.26 | c | 34.29 | 44.21 | b | 54.03 | a | 52.45 | b | 49.82 | b | 33.47 | a | 26.86 | b | ----- | z | 36.51 | a | |||
1991 | 19.65 | 28.46 | 25.77 | 29.67 | 35.10 | a | 40.48 | a | 53.55 | 53.06 | 47.13 | 36.97 | 27.53 | 21.13 | a | 34.88 | ||||||||||
1992 | 21.35 | 29.72 | 31.71 | 34.40 | 43.48 | 48.47 | 50.40 | a | 51.45 | 42.73 | d | 39.50 | g | 23.43 | b | 15.73 | a | 35.72 | a | |||||||
1993 | 10.71 | 11.96 | a | 26.75 | c | 29.86 | h | 40.92 | e | 41.15 | c | 40.47 | a | 43.50 | c | 45.93 | 37.39 | 18.00 | a | ----- | z | 31.68 | b | |||
1994 | ----- | z | 20.18 | 28.10 | 33.83 | a | 40.19 | 44.62 | a | 55.03 | 50.16 | 47.80 | 33.84 | 19.97 | 18.16 | 35.63 | a | |||||||||
1995 | 22.81 | j | 29.67 | d | 26.60 | a | 29.70 | c | 39.37 | a | 42.90 | a | 49.65 | e | 47.80 | a | 46.50 | b | 32.66 | b | 31.48 | a | 22.55 | 36.26 | a | |
1996 | 22.76 | b | 18.88 | d | 27.74 | 31.57 | 35.50 | a | ----- | z | 46.96 | e | 49.92 | e | 41.57 | b | 34.39 | c | 27.31 | d | 24.09 | i | 33.66 | b | ||
1997 | 20.13 | h | 24.27 | f | 28.50 | a | 28.96 | e | 41.80 | f | 42.04 | e | 50.61 | c | 52.43 | a | 45.73 | 34.03 | 29.33 | 18.12 | f | 38.95 | d | |||
1998 | 26.28 | b | 23.74 | a | 28.80 | a | 24.21 | b | 37.55 | 44.33 | 56.19 | 54.40 | a | 50.43 | b | 32.50 | a | 27.96 | d | 18.32 | c | 35.39 | ||||
1999 | 22.94 | 20.75 | 25.10 | b | ----- | z | 33.03 | b | 38.07 | a | 47.97 | 51.77 | a | 42.81 | c | 36.17 | b | 30.96 | c | 21.21 | b | 33.71 | a | |||
2000 | 19.30 | d | 26.00 | e | 25.44 | d | 31.37 | c | 37.28 | b | 42.96 | f | 48.89 | l | ----- | z | 42.00 | i | 34.55 | i | 17.53 | o | 18.00 | m | 27.88 | g |
2001 | 12.71 | j | 16.28 | j | 25.79 | l | 24.30 | j | 37.97 | 35.94 | l | 50.83 | m | 50.68 | l | 44.40 | e | 34.11 | d | 25.76 | a | 18.00 | c | 32.05 | g | |
2002 | 19.14 | b | 16.85 | a | 24.18 | i | 28.43 | b | 29.97 | b | 38.90 | 52.84 | 43.62 | o | 41.83 | 29.47 | a | 25.14 | a | 20.97 | a | 30.35 | b | |||
2003 | 25.86 | b | 22.14 | 35.03 | b | 30.43 | 33.74 | 38.90 | a | 55.57 | h | 51.52 | j | 43.47 | m | 38.60 | a | 23.92 | f | 22.38 | e | 30.89 | d | |||
2004 | 18.69 | e | 20.26 | f | 30.71 | g | 32.65 | d | 37.05 | j | 45.00 | f | 53.91 | h | 54.83 | h | 41.85 | j | 36.67 | g | 27.09 | g | 23.48 | h | 25.67 | j |
2005 | 19.08 | f | 22.85 | b | 30.04 | f | 31.00 | h | 40.35 | h | 40.86 | h | 52.89 | m | 50.55 | k | 42.50 | j | 35.68 | i | 25.95 | h | 15.25 | k | 22.85 | k |
2006 | 22.45 | k | 19.72 | j | 24.36 | i | 26.50 | l | 31.75 | o | 48.35 | j | 54.33 | m | 49.27 | i | 39.06 | m | 35.26 | l | 26.00 | l | 18.72 | m | ----- | z |
2007 | 14.14 | i | 22.06 | j | 27.25 | k | 27.44 | n | 35.78 | m | 41.58 | k | 54.56 | o | 50.71 | j | 41.61 | l | 31.16 | l | 24.56 | n | 17.78 | m | ----- | z |
2008 | 13.14 | j | 22.14 | h | 23.00 | j | 25.43 | i | 36.53 | l | 40.74 | k | 52.24 | j | 51.48 | j | 44.23 | h | 36.50 | i | 28.94 | n | 16.86 | i | ----- | z |
2009 | 20.70 | k | 20.15 | h | 23.48 | j | 27.90 | j | 36.95 | l | 46.65 | j | 54.36 | i | 50.28 | m | 43.05 | i | 30.43 | j | 24.10 | i | 13.33 | j | ----- | z |
2010 | 24.22 | m | 23.94 | k | 25.05 | i | 27.30 | j | 32.15 | k | 41.65 | j | 48.61 | m | 47.36 | i | 44.05 | i | 38.10 | a | 24.11 | b | 20.48 | b | 27.56 | i |
2011 | 18.52 | 19.61 | 26.42 | 26.93 | a | 33.10 | 39.80 | 48.35 | 53.16 | 48.07 | 35.25 | c | ----- | z | 17.61 | 33.35 | a | |||||||||
2012 | 20.90 | a | 21.86 | 25.56 | d | 32.00 | 37.40 | a | 41.17 | 53.97 | 53.68 | c | 48.70 | 35.13 | 28.63 | c | 19.52 | 34.88 | ||||||||
2013 | 13.88 | e | 20.52 | c | 27.27 | e | 28.61 | b | 39.30 | d | 44.93 | b | 56.68 | 53.16 | 43.41 | m | 31.46 | c | 26.86 | a | 14.83 | b | 32.50 | a | ||
2014 | 23.52 | 24.52 | e | 27.70 | a | 30.29 | f | 37.60 | a | 42.95 | i | 56.46 | e | 51.03 | b | 45.20 | 38.59 | b | 23.41 | h | 25.87 | 36.72 | c | |||
2015 | 25.61 | h | 29.61 | 30.87 | 30.60 | 39.90 | k | 53.90 | 54.42 | 52.71 | 43.93 | 40.55 | 21.53 | 7.61 | 36.57 | b | ||||||||||
2016 | 20.03 | 26.28 | 29.83 | b | 36.40 | 40.00 | 47.43 | 50.83 | y | 53.84 | 42.63 | 35.10 | 30.07 | 14.03 | 34.15 | a | ||||||||||
2017 | 10.55 | 23.50 | x | 32.33 | g | 29.52 | c | 40.45 | 44.00 | t | ----- | z | 56.81 | 17.37 | 31.97 | 27.97 | 17.84 | 29.06 | d | |||||||
2018 | 26.97 | 20.11 | 24.13 | a | 30.77 | 41.87 | a | 43.40 | 52.59 | n | 51.52 | 41.85 | j | 40.00 | 23.07 | b | 14.92 | r | 33.54 | c | ||||||
2019 | 21.84 | 18.85 | a | 25.43 | c | ----- | z | ----- | z | 43.20 | 51.65 | 52.90 | 44.70 | 28.35 | 27.33 | 22.68 | 33.69 | b | ||||||||
2020 | 21.67 | g | 25.55 | 26.74 | 33.80 | 40.74 | 42.47 | o | 53.13 | 54.61 | 49.93 | a | 36.03 | 25.37 | 22.42 | 36.83 | b | |||||||||
2021 | 25.06 | 24.80 | c | 27.48 | 31.69 | d | 36.39 | 51.63 | 60.06 | 53.61 | 46.93 | 37.13 | 35.83 | 22.10 | 37.73 | |||||||||||
2022 | 25.39 | 22.04 | 27.23 | 27.54 | b | 32.06 | 45.93 | 57.04 | c | 59.39 | 50.76 | a | 41.26 | 17.17 | 14.55 | 35.03 | ||||||||||
2023 | 17.84 | 17.61 | 19.61 | 30.23 | 43.00 | 47.60 | 57.03 | 54.13 | 44.07 | b | 34.42 | 26.30 | 25.55 | b | 34.78 | |||||||||||
2024 | 25.55 | 25.55 | 26.34 | b | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 25.81 | i | ||
Period of Record Statistics | ||||||||||||||||||||||||||
MEAN | 17.63 | 21.62 | 25.46 | 29.71 | 36.16 | 42.80 | 50.40 | 49.86 | 42.72 | 34.28 | 25.56 | 19.77 | 32.60 | |||||||||||||
S.D. | 5.73 | 4.28 | 3.26 | 3.03 | 3.26 | 3.55 | 3.59 | 3.67 | 5.03 | 3.35 | 3.53 | 4.33 | 2.35 | |||||||||||||
SKEW | -0.67 | -0.09 | 0.17 | -0.08 | 0.08 | 0.45 | 0.04 | -0.11 | -1.88 | -0.07 | -0.11 | -0.52 | -0.23 | |||||||||||||
MAX | 28.28 | 29.72 | 35.03 | 36.40 | 43.48 | 53.90 | 60.06 | 59.39 | 50.76 | 43.35 | 35.83 | 29.23 | 37.73 | |||||||||||||
MIN | 0.61 | 11.96 | 19.30 | 23.40 | 29.13 | 36.41 | 40.47 | 41.16 | 17.37 | 23.28 | 17.17 | 7.61 | 27.36 | |||||||||||||
YRS | 66 | 73 | 70 | 70 | 72 | 68 | 70 | 70 | 68 | 73 | 70 | 67 | 32 |