| Hopland Research and Extension Center Headquarters | ||||||||||||
| Rainfall (Precipitation) by Month | ||||||||||||
| Jan | Feb | Mar | April | May | Jun | Jul | Aug | Sept | Oct | Nov | Dec | |
| 1952 | 0.31 | 2.72 | 17.10 | |||||||||
| 1953 | 10.91 | 0.33 | 4.12 | 3.12 | 1.67 | 0.85 | 0.00 | 0.26 | 0.00 | 1.73 | 5.50 | 2.78 |
| 1954 | 12.49 | 5.32 | 5.70 | 2.66 | 0.01 | 1.07 | 0.00 | 1.07 | 0.12 | 0.73 | 5.89 | 6.92 |
| 1955 | 3.55 | 2.10 | 0.54 | 3.92 | 0.00 | 0.00 | 0.00 | 0.00 | 0.39 | 0.50 | 4.29 | 19.44 |
| 1956 | 15.14 | 7.98 | 0.88 | 1.50 | 0.73 | 0.09 | 0.02 | 0.00 | 0.02 | 3.03 | 0.17 | 0.67 |
| 1957 | 7.07 | 8.42 | 3.64 | 2.57 | 3.77 | 0.00 | 0.00 | 0.00 | 3.97 | 5.70 | 1.49 | 5.69 |
| 1958 | 8.95 | 19.50 | 7.62 | 6.04 | 0.60 | 0.87 | 0.02 | 0.00 | 0.00 | 0.22 | 1.40 | 1.68 |
| 1959 | 12.12 | 8.09 | 1.69 | 0.45 | 0.00 | 0.00 | 0.00 | 0.00 | 2.02 | 0.03 | 0.04 | 1.44 |
| 1960 | 5.83 | 9.30 | 5.68 | 1.54 | 2.15 | 0.00 | 0.00 | 0.00 | 0.00 | 0.77 | 5.88 | 7.38 |
| 1961 | 4.51 | 3.92 | 5.92 | 1.47 | 0.80 | 0.00 | 0.00 | 0.00 | 0.19 | 0.51 | 8.39 | 3.80 |
| 1962 | 1.47 | 10.92 | 4.93 | 0.57 | 0.63 | 0.00 | 0.00 | 0.11 | 0.52 | 8.79 | 2.35 | 4.04 |
| 1963 | 4.52 | 4.82 | 7.04 | 7.02 | 1.17 | 0.00 | 0.00 | 0.00 | 0.09 | 3.77 | 7.56 | 1.50 |
| 1964 | 6.46 | 0.26 | 2.56 | 0.86 | 0.84 | 0.62 | 0.00 | 0.00 | 0.00 | 2.58 | 8.20 | 16.19 |
| 1965 | 8.54 | 1.25 | 1.03 | 5.24 | 0.00 | 0.00 | 0.00 | 0.53 | 0.03 | 0.16 | 9.57 | 4.95 |
| 1966 | 9.52 | 3.41 | 1.74 | 1.13 | 0.24 | 0.04 | 0.00 | 0.24 | 0.12 | 0.00 | 9.43 | 7.55 |
| 1967 | 10.06 | 0.38 | 7.58 | 4.66 | 0.37 | 1.41 | 0.00 | 0.00 | 0.01 | 1.97 | 3.23 | 5.28 |
| 1968 | 9.96 | 4.66 | 4.84 | 0.40 | 0.74 | 0.00 | 0.00 | 2.01 | 0.06 | 1.80 | 3.94 | 13.61 |
| 1969 | 14.58 | 10.40 | 1.22 | 2.38 | 0.00 | 0.05 | 0.00 | 0.00 | 0.02 | 1.97 | 2.08 | 12.72 |
| 1970 | 20.57 | 4.02 | 2.62 | 0.33 | 0.12 | 0.62 | 0.00 | 0.00 | 0.00 | 1.80 | 8.05 | 11.60 |
| 1971 | 5.50 | 0.48 | 6.31 | 1.36 | 1.08 | 0.01 | 0.00 | 0.15 | 0.30 | 0.47 | 3.17 | 7.23 |
| 1972 | 2.95 | 3.32 | 1.53 | 2.23 | 0.50 | 0.06 | 0.00 | 0.03 | 1.21 | 3.39 | 5.76 | 5.60 |
| 1973 | 13.13 | 8.78 | 3.81 | 0.19 | 0.06 | 0.00 | 0.00 | 0.00 | 0.91 | 2.74 | 16.13 | 7.30 |
| 1974 | 10.79 | 4.18 | 12.87 | 2.41 | 0.13 | 0.00 | 0.91 | 0.19 | 0.00 | 1.55 | 1.41 | 5.51 |
| 1975 | 2.45 | 11.35 | 10.39 | 1.71 | 0.03 | 0.08 | 0.21 | 0.44 | 0.00 | 4.10 | 1.54 | 1.85 |
| 1976 | 0.45 | 2.73 | 1.74 | 3.05 | 0.00 | 0.00 | 0.02 | 1.49 | 0.13 | 0.44 | 2.51 | 0.61 |
| 1977 | 2.31 | 2.65 | 3.00 | 0.15 | 2.14 | 0.00 | 0.00 | 0.03 | 2.13 | 1.33 | 4.08 | 8.17 |
| 1978 | 16.97 | 8.14 | 5.23 | 5.58 | 0.22 | 0.03 | 0.00 | 0.02 | 2.13 | 0.00 | 1.20 | 0.66 |
| 1979 | 8.82 | 8.25 | 4.01 | 2.19 | 1.07 | 0.00 | 0.00 | 0.00 | 0.17 | 4.80 | 7.09 | 7.56 |
| 1980 | 7.18 | 10.82 | 2.19 | 2.25 | 0.65 | 0.31 | 0.01 | 0.00 | 0.18 | 1.30 | 0.77 | 7.06 |
| 1981 | 9.32 | 3.07 | 3.50 | 0.83 | 0.57 | 0.00 | 0.07 | 0.00 | 0.61 | 5.52 | 13.32 | 9.19 |
| 1982 | 7.55 | 4.61 | 7.47 | 5.92 | 0.00 | 0.06 | 0.00 | 0.00 | 0.72 | 5.00 | 7.59 | 9.32 |
| 1983 | 10.05 | 11.14 | 17.07 | 6.09 | 0.62 | 0.07 | 0.06 | 0.28 | 1.04 | 1.35 | 14.14 | 13.23 |
| 1984 | 0.63 | 4.78 | 3.07 | 1.73 | 0.17 | 0.37 | 0.00 | 0.08 | 0.12 | 2.85 | 11.93 | 2.75 |
| 1985 | 0.69 | 2.00 | 5.08 | 0.10 | 0.03 | 0.02 | 0.01 | 0.00 | 2.34 | 2.18 | 5.11 | 3.56 |
| 1986 | 7.04 | 17.36 | 6.60 | 1.08 | 0.84 | 0.00 | 0.00 | 0.00 | 1.86 | 0.83 | 0.38 | 3.03 |
| 1987 | 5.74 | 4.67 | 6.68 | 0.14 | 0.99 | 0.00 | 0.00 | 0.00 | 0.00 | 2.30 | 3.82 | 9.70 |
| 1988 | 8.32 | 0.31 | 0.29 | 2.68 | 0.90 | 0.56 | 0.00 | 0.00 | 0.00 | 0.22 | 5.77 | 3.75 |
| 1989 | 1.93 | 1.23 | 11.79 | 1.00 | 0.35 | 0.75 | 0.00 | 0.00 | 2.63 | 5.32 | 1.83 | 0.00 |
| 1990 | 5.91 | 3.53 | 2.12 | 0.36 | 3.34 | 0.07 | 0.00 | 0.09 | 0.59 | 1.26 | 0.61 | 1.84 |
| 1991 | 0.65 | 3.04 | 15.63 | 0.75 | 0.44 | 0.54 | 0.13 | 0.02 | 0.01 | 1.82 | 1.88 | 3.17 |
| 1992 | 3.37 | 9.06 | 4.78 | 1.05 | 0.23 | 1.07 | 0.00 | 0.00 | 0.01 | 3.70 | 1.23 | 12.38 |
| 1993 | 13.04 | 7.75 | 2.89 | 2.52 | 3.70 | 0.70 | 0.00 | 0.00 | 0.00 | 0.79 | 2.27 | 4.82 |
| 1994 | 5.40 | 6.22 | 0.41 | 2.32 | 1.11 | 0.29 | 0.00 | 0.00 | 0.03 | 0.46 | 5.77 | 4.63 |
| 1995 | 25.54 | 0.57 | 17.67 | 4.14 | 2.88 | 0.43 | 0.00 | 0.00 | 0.00 | 0.00 | 0.21 | 13.76 |
| 1996 | 8.43 | 9.61 | 3.47 | 3.45 | 2.51 | 0.83 | 0.00 | 0.00 | 0.12 | 1.58 | 4.33 | 17.16 |
| 1997 | 12.21 | 1.29 | 2.11 | 0.59 | 1.06 | 1.11 | 0.00 | 0.88 | 0.66 | 1.60 | 8.47 | 3.64 |
| 1998 | 12.78 | 19.77 | 5.90 | 2.78 | 4.37 | 0.03 | 0.00 | 0.00 | 0.01 | 0.96 | 7.23 | 2.92 |
| 1999 | 3.98 | 11.29 | 5.86 | 2.24 | 0.14 | 0.04 | 0.00 | 0.00 | 0.16 | 1.23 | 4.77 | 1.04 |
| 2000 | 7.20 | 12.40 | 2.76 | 2.36 | 1.22 | 0.47 | 0.00 | 0.00 | 0.51 | 3.19 | 1.44 | 1.22 |
| 2001 | 6.17 | 8.44 | 3.32 | 1.12 | 0.00 | 0.37 | 0.00 | 0.00 | 0.17 | 1.04 | 8.91 | 9.71 |
| 2002 | 4.37 | 1.85 | 2.21 | 0.69 | 0.88 | 0.00 | 0.00 | 0.00 | 0.00 | 0.02 | 3.97 | 21.73 |
| 2003 | 3.89 | 1.99 | 4.26 | 7.57 | 0.80 | 0.00 | 0.08 | 0.01 | 0.15 | 0.26 | 4.77 | 13.01 |
| 2004 | 4.20 | 12.20 | 1.33 | 1.08 | 0.00 | 0.05 | 0.00 | 0.00 | 0.22 | 3.53 | 2.20 | 9.28 |
| 2005 | 7.48 | 3.26 | 6.18 | 2.38 | 4.37 | 1.69 | 0.00 | 0.00 | 0.02 | 0.92 | 4.37 | 18.34 |
| 2006 | 6.99 | 4.66 | 10.61 | 7.98 | 0.41 | 0.00 | 0.00 | 0.00 | 0.00 | 0.31 | 3.51 | 6.04 |
| 2007 | 0.38 | 9.75 | 0.53 | 2.15 | 0.49 | 0.00 | 0.17 | 0.00 | 0.14 | 2.28 | 0.59 | 6.18 |
| 2008 | 12.00 | 4.91 | 0.69 | 0.20 | 0.00 | 0.00 | 0.00 | 0.00 | 0.43 | 1.37 | 3.95 | 3.26 |
| 2009 | 0.98 | 9.71 | ||||||||||
| Mean | 7.60 | 6.25 | 4.91 | 2.36 | 0.93 | 0.28 | 0.03 | 0.14 | 0.49 | 1.90 | 4.71 | 7.10 |