| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1952 | ----- | z | ----- | z | ----- | z | 35.37 | 42.13 | a | 48.47 | 54.83 | a | 55.70 | a | 46.47 | 33.84 | 22.90 | 20.66 | b | 40.04 | c | |||||
| 1953 | 27.21 | b | 21.41 | f | 27.28 | b | 31.62 | d | 35.11 | d | 45.26 | c | 53.83 | a | 53.79 | c | 43.32 | b | 34.31 | b | 30.07 | 16.23 | 36.18 | a | ||
| 1954 | 21.87 | a | 25.39 | 26.93 | a | 35.25 | b | 42.29 | 47.10 | 56.58 | 47.70 | a | 44.87 | 34.06 | 26.37 | 18.42 | 35.57 | |||||||||
| 1955 | 6.97 | 6.30 | a | 20.43 | a | 29.07 | a | 39.90 | 46.77 | 51.00 | 54.57 | a | 40.67 | i | 31.43 | q | 21.71 | b | 27.21 | b | 30.39 | b | ||||
| 1956 | 27.23 | a | 13.18 | a | 24.25 | c | 34.68 | h | 44.19 | 46.00 | 51.19 | 45.67 | a | 40.07 | 34.48 | f | 18.93 | 19.21 | b | 32.99 | b | |||||
| 1957 | 15.94 | 26.22 | a | 30.32 | c | ----- | z | 40.53 | a | 47.03 | 53.43 | a | 54.97 | 39.57 | 36.87 | 24.27 | 22.48 | d | 35.60 | a | ||||||
| 1958 | 18.74 | 26.32 | 28.16 | 33.07 | 42.35 | 47.40 | 49.65 | 53.90 | 41.33 | 32.32 | 22.80 | 23.06 | 34.93 | |||||||||||||
| 1959 | 22.68 | 24.29 | 25.80 | k | 33.13 | 38.00 | g | 48.85 | j | ----- | z | ----- | z | 41.23 | h | 32.00 | i | 20.62 | i | 16.04 | h | 26.70 | i | |||
| 1960 | 15.50 | k | 18.55 | 27.52 | 32.10 | 36.65 | 45.57 | 50.74 | 43.92 | g | 43.27 | 33.86 | c | 29.20 | 18.52 | 33.60 | b | |||||||||
| 1961 | 14.32 | 23.75 | 28.35 | 31.36 | b | 39.55 | 48.27 | 54.00 | b | 54.82 | c | 38.37 | 31.48 | b | 21.90 | 15.00 | b | 33.43 | ||||||||
| 1962 | 8.10 | a | 21.11 | a | 22.53 | a | 32.36 | e | ----- | z | 47.22 | l | 53.59 | b | 50.58 | 39.93 | b | 32.73 | a | ----- | z | 14.96 | f | 32.62 | d | |
| 1963 | 8.65 | 23.96 | c | 21.11 | c | 28.03 | 41.07 | a | 42.73 | 50.73 | a | 55.06 | 45.52 | e | ----- | z | 27.30 | c | 16.32 | 32.77 | a | |||||
| 1964 | 6.27 | a | ----- | z | 18.43 | a | 32.90 | ----- | z | ----- | z | 52.29 | 50.07 | a | 39.97 | 31.84 | 22.93 | 23.94 | 30.96 | c | ||||||
| 1965 | 22.55 | 21.39 | 21.90 | a | 36.27 | 39.10 | 46.30 | 54.52 | 51.52 | 40.03 | 32.97 | a | 32.27 | 21.90 | a | 35.06 | ||||||||||
| 1966 | 17.73 | a | 18.43 | 25.71 | 31.37 | 40.52 | 46.40 | 53.26 | 49.13 | 45.30 | 30.73 | a | 27.87 | 19.61 | 33.84 | |||||||||||
| 1967 | 15.39 | 20.54 | 29.03 | 31.60 | 38.19 | 45.97 | a | 53.50 | a | 53.03 | 43.80 | 31.65 | 25.73 | 13.71 | 33.51 | |||||||||||
| 1968 | 8.06 | 24.39 | a | 28.84 | 31.83 | 38.77 | 47.55 | a | 53.20 | a | 49.40 | a | 38.52 | a | 32.43 | a | 25.42 | d | 15.19 | d | 32.80 | |||||
| 1969 | 24.10 | a | 23.57 | 22.64 | c | 34.32 | b | 44.31 | b | 47.37 | 55.00 | 55.77 | a | 48.25 | b | 31.84 | 25.03 | 19.86 | c | 36.00 | ||||||
| 1970 | 19.10 | a | 24.39 | 26.68 | 29.42 | d | 40.48 | 48.07 | a | 55.06 | 55.87 | 39.00 | a | 29.81 | 30.70 | 17.77 | 34.70 | |||||||||
| 1971 | 18.35 | 23.22 | a | 25.86 | c | 33.60 | 38.55 | 47.87 | 52.60 | a | 54.60 | a | 37.72 | a | 32.14 | b | 25.07 | a | 11.58 | e | 33.43 | |||||
| 1972 | 15.84 | l | 21.48 | f | 29.32 | c | 32.50 | b | 40.59 | b | 50.89 | b | 52.81 | e | 51.17 | g | 43.24 | a | 38.45 | b | ----- | z | 12.21 | b | 37.50 | d |
| 1973 | 8.62 | e | 20.78 | a | 26.61 | 30.48 | a | 37.77 | 46.08 | f | 50.08 | s | 52.35 | 41.93 | c | 34.26 | 27.89 | c | 23.18 | c | 30.39 | b | ||||
| 1974 | 15.50 | e | 18.33 | a | 30.54 | e | 34.08 | f | 41.61 | 48.20 | 54.87 | a | 46.65 | 40.52 | a | 36.27 | a | 26.89 | b | 18.29 | 34.33 | a | ||||
| 1975 | 10.77 | 23.15 | a | 28.43 | a | 30.83 | 37.57 | a | 43.69 | a | 55.47 | a | 49.65 | 41.48 | a | 32.67 | a | 23.40 | 18.87 | 33.00 | ||||||
| 1976 | 9.71 | 17.72 | 21.61 | 32.07 | 40.46 | c | ----- | z | 54.37 | l | ----- | z | 39.80 | t | 29.29 | c | 23.38 | d | 14.89 | m | 24.89 | e | ||||
| 1977 | 12.35 | h | 3.00 | t | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z |
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 15.81 | 21.19 | 25.76 | 32.21 | 40.08 | 46.84 | 53.28 | 52.13 | 41.93 | 33.04 | 25.55 | 18.78 | 34.21 | |||||||||||||
| S.D. | 6.71 | 4.74 | 3.46 | 2.03 | 2.29 | 1.77 | 1.78 | 3.19 | 2.90 | 2.22 | 3.28 | 3.94 | 1.09 | |||||||||||||
| SKEW | 0.14 | -1.65 | -0.53 | 0.04 | -0.09 | -0.28 | -0.31 | -0.54 | 0.48 | 0.67 | 0.19 | 0.05 | 0.29 | |||||||||||||
| MAX | 27.23 | 26.32 | 30.54 | 36.27 | 44.31 | 50.89 | 56.58 | 55.87 | 48.25 | 38.45 | 32.27 | 27.21 | 36.00 | |||||||||||||
| MIN | 6.27 | 6.30 | 18.43 | 28.03 | 35.11 | 42.73 | 49.65 | 45.67 | 37.72 | 29.29 | 18.93 | 11.58 | 32.80 | |||||||||||||
| YRS | 22 | 21 | 23 | 22 | 22 | 20 | 22 | 21 | 22 | 21 | 22 | 22 | 11 | |||||||||||||