Illinois State Water Survey
Institute of Natural Resource Sustainability
University of Illinois
Institute of Natural Resource Sustainability
University of Illinois
Illinois State Climatologist Office
Jim Angel, state climatologist
Pan Evaporation Across Illinois
Jim Angel, state climatologistPan evaporation is measured at a few sites across Illinois during the warm season. The amounts are in inches of water lost per month. Evaporation from a natural body of water is usually at a lower rate. Most textbooks suggest multiplying the pan evaporation by 0.75 to correct for this. Data Disclaimer.
Data updated through 2006 if available.
Chicago | De Kalb | Urbana | Hennepin | Springfield | Perry | Belleville | Carlyle | Dixon Springs
| April | May | June | July | August | September | October | |
| 1997 | - | - | - | - | 4.96 | 3.72 | 2.95 |
| 1998 | - | 5.23 | 5.81 | 6.19 | 4.57 | 3.95 | 2.77 |
| 1999 | - | 4.69 | 5.77 | 7.32 | 4.85 | 3.86 | 2.42 |
| 2000 | - | 4.14 | 8.04 | 5.20 | 4.64 | 4.02 | 2.63 |
| 2001 | - | 5.29 | 5.15 | 6.05 | 4.96 | 3.41 | 3.72 |
| 2002 | - | - | 4.68 | 5.98 | 5.74 | 3.76 | 1.94 |
| 2003 | - | 4.33 | 5.37 | 6.05 | 5.32 | 3.74 | 2.30 |
| 2004 | - | - | 4.70 | 5.24 | 4.36 | 4.02 | 2.31 |
| 2005 | - | - | 6.03 | 6.30 | 5.54 | 3.97 | 2.34 |
| 2006 | - | - | 5.44 | 5.43 | 5.24 | 4.39 | - |
| Average | - | 4.74 | 5.67 | 5.97 | 5.02 | 3.88 | 2.60 |
| April | May | June | July | August | September | October | |
| 1987 | - | - | - | - | - | 7.66 | - |
| 1988 | - | - | - | 9.90 | 8.31 | 5.12 | - |
| 1989 | - | - | - | - | - | - | - |
| 1990 | - | 5.88 | 7.92 | 8.36 | 7.02 | 4.56 | - |
| 1991 | - | - | - | - | - | - | - |
| 1992 | - | - | - | - | - | - | - |
| 1993 | - | - | - | - | - | - | - |
| 1994 | - | - | - | - | - | - | - |
| 1995 | - | - | - | - | - | - | - |
| 1996 | - | - | - | - | - | - | - |
| 1997 | - | 5.04 | 6.81 | 6.91 | 4.51 | 3.51 | 2.95 |
| 1998 | 3.14 | 5.57 | 5.78 | 7.07 | 4.94 | 3.89 | 2.42 |
| 1999 | 3.85 | 5.72 | 6.09 | 7.53 | 4.95 | 4.72 | 3.06 |
| 2000 | 3.92 | 4.80 | 5.82 | 7.29 | - | 4.59 | 3.32 |
| 2001 | 4.73 | 6.04 | 6.01 | 7.43 | 6.20 | 3.94 | 2.43 |
| 2002 | 6.14 | 5.20 | 6.36 | 8.04 | 5.94 | 4.08 | 2.36 |
| 2003 | - | 5.18 | 6.60 | 7.18 | 7.18 | 3.82 | - |
| 2004 | 5.04 | 4.96 | 5.84 | 5.94 | 4.18 | 3.36 | 1.61 |
| 2005 | 3.43 | 5.28 | 7.47 | 7.45 | 6.68 | 4.49 | 2.45 |
| 2006 | 5.14 | 6.35 | 6.60 | 6.63 | 5.40 | 3.89 | 3.39 |
| Average | 4.42 | 5.46 | 6.48 | 7.48 | 5.94 | 4.44 | 2.67 |
| April | May | June | July | August | September | October | |
| 1980 | 3.51 | 4.94 | 5.88 | - | 5.22 | 3.59 | - |
| 1981 | 4.13 | 3.92 | 5.37 | 4.82 | 4.38 | 4.19 | 3.47 |
| 1982 | - | 5.27 | 5.26 | 5.58 | 4.73 | 3.30 | 2.79 |
| 1983 | - | - | - | - | 6.44 | - | 2.91 |
| 1984 | - | 4.89 | 7.39 | 6.30 | 5.41 | 3.87 | - |
| 1985 | - | 5.64 | 5.52 | 6.05 | - | - | - |
| 1986 | 5.11 | 5.72 | 7.33 | 7.63 | 6.08 | 4.36 | 2.50 |
| 1987 | - | 7.85 | 7.95 | 6.39 | 5.98 | 4.79 | - |
| 1988 | 5.01 | 8.00 | 9.08 | 7.93 | 6.61 | 4.85 | 2.80 |
| 1989 | - | 5.02 | 6.53 | 6.36 | 5.60 | 4.59 | - |
| 1990 | - | - | 6.63 | 6.27 | 5.20 | 4.19 | - |
| 1991 | 4.20 | 5.36 | 7.23 | 8.27 | 6.30 | 4.99 | - |
| 1992 | - | 5.80 | 6.88 | 5.92 | 5.60 | 4.05 | - |
| 1993 | - | 5.79 | 6.14 | 6.45 | 5.39 | - | - |
| 1994 | - | 6.51 | 7.18 | 7.11 | 5.85 | 4.48 | - |
| 1995 | - | 4.69 | 6.42 | 8.15 | 6.16 | 4.52 | - |
| 1996 | - | - | 6.20 | 7.15 | 6.01 | 4.29 | - |
| 1997 | - | 5.73 | 5.33 | 6.96 | 5.22 | 4.62 | - |
| 1998 | 3.93 | 5.80 | 7.84 | 6.15 | 5.38 | 5.30 | 2.94 |
| 1999 | - | 5.83 | 5.88 | 6.18 | 5.60 | 5.56 | - |
| 2000 | 4.04 | 5.36 | 6.02 | 5.62 | 5.67 | 4.56 | 3.14 |
| 2001 | - | 5.87 | 5.89 | 6.40 | 6.07 | 3.85 | - |
| 2002 | - | 4.79 | 6.41 | 7.55 | 5.74 | 4.62 | 2.84 |
| 2003 | - | - | 5.77 | 6.31 | 6.16 | 5.80 | 2.87 |
| 2004 | - | 5.56 | 6.51 | 5.94 | 5.27 | 5.07 | - |
| 2005 | 4.51 | 6.21 | 7.85 | 8.04 | 6.17 | 5.27 | 3.00 |
| 2006 | 4.58 | 4.98 | 6.40 | - | 5.15 | 3.51 | 3.64 |
| Average | 4.34 | 5.63 | 6.57 | 6.65 | 5.67 | 4.51 | 2.99 |
| April | May | June | July | August | September | October | |
| 1980 | - | 8.85 | 6.55 | - | 7.00 | 5.04 | - |
| 1981 | - | - | 7.95 | 6.84 | - | 4.28 | - |
| 1982 | - | - | 5.40 | 8.68 | 7.13 | 3.30 | - |
| 1983 | - | - | 7.10 | 9.37 | 6.28 | - | - |
| 1984 | - | - | 7.76 | 5.57 | 7.77 | 4.01 | 3.08 |
| 1985 | - | 7.04 | 8.68 | 5.22 | 7.17 | 9.17 | - |
| 1986 | - | - | 7.04 | 7.14 | 6.55 | 3.88 | 4.69 |
| 1987 | - | 8.03 | 7.45 | 9.09 | 6.80 | 4.14 | - |
| 1988 | - | - | - | - | 8.45 | 4.80 | - |
| 1989 | - | 6.62 | 7.07 | 7.76 | 6.36 | 4.49 | - |
| 1990 | - | - | - | - | - | - | - |
| 1991 | - | - | 8.29 | 8.96 | 7.85 | 7.05 | - |
| 1992 | - | - | 7.54 | 6.31 | 5.78 | 5.23 | - |
| 1993 | - | - | - | - | - | - | - |
| 1994 | - | - | - | - | - | 4.61 | 3.08 |
| 1995 | - | 4.75 | 6.40 | - | 6.90 | 5.41 | 5.33 |
| 1996 | - | - | - | 6.89 | 6.21 | 3.65 | 6.83 |
| 1997 | - | - | 7.89 | 9.32 | 8.68 | - | - |
| 1998 | - | - | - | 7.74 | 6.52 | 5.66 | - |
| 1999 | - | - | - | - | - | - | - |
| 2000 | - | - | - | - | - | - | - |
| 2001 | - | 5.59 | 5.58 | 6.61 | 5.93 | 4.76 | - |
| 2002 | - | 5.62 | 6.07 | 7.51 | 6.14 | 5.46 | - |
| 2003 | - | - | - | - | - | - | - |
| 2004 | - | - | - | - | - | - | - |
| 2005 | - | - | 7.58 | 7.75 | 6.52 | - | - |
| Average | - | 5.62 | 6.57 | 6.69 | 5.66 | 4.43 | 4.60 |
| April | May | June | July | August | September | October | |
| 1980 | - | - | 7.57 | - | 7.15 | 5.65 | 4.12 |
| 1981 | - | 6.36 | 7.98 | 7.04 | 6.64 | 5.26 | 3.87 |
| 1982 | - | - | - | - | - | - | - |
| 1983 | 4.73 | 6.92 | 8.27 | 10.31 | - | - | - |
| 1984 | 5.16 | 7.04 | 8.99 | 8.39 | 8.49 | 5.66 | 3.34 |
| 1985 | 6.36 | 8.61 | 7.02 | 7.26 | 6.36 | 6.34 | 3.73 |
| 1986 | 7.17 | 6.75 | 8.36 | 9.05 | 7.79 | 5.96 | 5.91 |
| 1987 | 5.68 | 10.10 | 9.42 | 7.75 | 7.55 | 6.55 | 4.28 |
| 1988 | 6.91 | 10.91 | 11.96 | 11.59 | 9.27 | 6.66 | 4.58 |
| 1989 | 6.30 | 7.04 | 8.39 | 8.88 | 7.48 | 5.98 | 5.06 |
| 1990 | 5.90 | 5.72 | 8.48 | 9.10 | 6.72 | 5.54 | 5.72 |
| Average | 6.03 | 7.72 | 8.64 | 8.82 | 7.49 | 5.96 | 4.51 |
| April | May | June | July | August | September | October | |
| 1996 | - | 6.06 | 7.27 | 8.19 | 6.80 | 4.38 | - |
| 1997 | 4.56 | 7.02 | 6.88 | 8.67 | 6.77 | 5.36 | - |
| 1998 | - | 6.54 | 8.80 | 7.26 | 6.67 | 5.28 | - |
| 1999 | 4.43 | 7.82 | 7.01 | 9.50 | 8.03 | 6.86 | - |
| 2000 | 5.84 | 8.24 | 8.68 | 8.61 | 8.62 | 7.53 | - |
| 2001 | 7.41 | 7.62 | 7.32 | 8.06 | 7.57 | 5.57 | - |
| 2002 | - | 6.52 | 7.97 | 8.59 | 7.61 | 6.49 | - |
| Average | 5.56 | 7.12 | 7.70 | 8.41 | 7.44 | 5.92 | 4.28 |
| April | May | June | July | August | September | October | |
| 1986 | - | - | - | 9.05 | 8.04 | 5.83 | - |
| 1987 | - | 8.25 | 9.08 | 8.37 | 6.74 | 5.50 | - |
| 1988 | - | 7.68 | 9.27 | 9.27 | 7.57 | 5.03 | - |
| 1989 | - | 6.45 | 6.78 | - | 6.05 | 4.81 | - |
| 1990 | - | 6.60 | 7.98 | 8.64 | 6.60 | 5.81 | - |
| 1991 | - | 5.31 | 7.84 | 8.89 | 7.33 | 5.62 | - |
| 1992 | - | 6.41 | 7.81 | 7.71 | 6.57 | 5.48 | - |
| 1993 | - | 6.82 | 7.29 | 8.61 | 6.68 | 5.23 | - |
| 1994 | - | 7.59 | 7.53 | 7.86 | 6.71 | 6.23 | - |
| 1995 | - | 6.47 | 6.77 | 8.32 | 7.22 | 5.75 | - |
| 1996 | - | 8.25 | 7.13 | 7.48 | 7.48 | 5.05 | - |
| 1997 | - | 6.87 | 7.15 | 8.15 | 5.96 | 5.17 | - |
| 1998 | - | 7.01 | 8.84 | 7.16 | 7.01 | 4.28 | - |
| 1999 | - | 6.87 | 7.24 | - | 7.36 | 6.87 | - |
| 2000 | - | 6.56 | 9.86 | 6.81 | 6.45 | - | - |
| 2001 | - | 7.26 | 8.50 | 7.72 | 7.99 | 5.17 | - |
| 2002 | - | 6.81 | 8.18 | 8.56 | 7.06 | 5.72 | - |
| 2003 | - | 5.90 | 7.22 | 8.43 | 7.36 | 5.40 | - |
| 2004 | - | 6.34 | 6.91 | 7.88 | 6.74 | 5.60 | - |
| 2005 | - | 7.24 | 9.04 | 8.34 | 7.33 | 6.25 | - |
| 2006 | - | 6.96 | 8.60 | 7.52 | 7.39 | 5.25 | - |
| Average | - | 6.88 | 7.95 | 8.15 | 7.03 | 5.50 | - |
| April | May | June | July | August | September | October | |
| 1980 | 4.84 | 5.99 | 9.24 | - | 9.14 | 5.90 | 4.38 |
| 1981 | 7.02 | 4.67 | 7.08 | 8.26 | 6.57 | 5.45 | 3.57 |
| 1982 | - | 7.61 | 6.03 | 7.71 | 6.20 | 4.80 | - |
| 1983 | - | 6.88 | 7.37 | 9.37 | 8.58 | 6.96 | 4.27 |
| 1984 | - | 6.30 | - | 8.29 | 8.32 | 5.89 | 3.20 |
| 1985 | 5.77 | 6.69 | 6.74 | 8.44 | 5.81 | 6.47 | 4.06 |
| 1986 | - | 6.23 | 8.57 | 9.35 | 7.32 | - | 3.84 |
| 1987 | - | - | 8.50 | 8.13 | 7.40 | 5.95 | - |
| 1988 | - | - | 10.32 | 9.35 | 8.44 | 5.70 | - |
| 1989 | - | - | 7.57 | 8.38 | 6.94 | 4.81 | - |
| 1990 | - | - | - | - | - | - | - |
| 1991 | - | - | - | - | - | - | - |
| 1992 | - | - | - | - | - | - | - |
| 1993 | - | - | 6.89 | 7.57 | 7.09 | 4.31 | - |
| 1994 | - | - | 7.39 | 7.43 | 6.95 | 5.04 | - |
| 1995 | - | - | - | - | - | - | - |
| 1996 | - | - | - | - | 6.67 | - | - |
| 1997 | - | - | 5.79 | 8.14 | 6.31 | 4.68 | - |
| 1998 | - | - | 5.70 | 5.60 | 6.08 | 5.77 | - |
| 1999 | - | - | 6.49 | 7.81 | 6.40 | 6.35 | - |
| 2000 | - | - | 6.60 | 7.08 | - | 5.09 | - |
| 2001 | - | - | - | - | - | - | - |
| 2002 | - | - | - | - | - | - | - |
| Average | 5.88 | 6.34 | 7.35 | 8.06 | 7.14 | 5.54 | 3.89 |
| April | May | June | July | August | September | October | November | |
| 1983 | 3.19 | 5.48 | 6.12 | 7.39 | 7.73 | 5.93 | 3.18 | 2.14 |
| 1984 | 3.77 | 5.46 | 7.11 | 6.64 | 5.75 | 5.00 | 2.51 | 2.04 |
| 1985 | 4.77 | 5.47 | 6.06 | 6.73 | 5.29 | 4.85 | 2.98 | - |
| 1986 | 5.54 | 5.50 | 6.51 | 8.40 | 6.73 | 4.94 | 2.59 | - |
| 1987 | - | - | - | - | - | 5.74 | 4.02 | 2.94 |
| 1988 | 5.90 | 7.08 | 8.86 | 7.33 | 7.50 | 4.35 | 3.22 | 2.22 |
| 1989 | 4.56 | 5.32 | 5.50 | 6.09 | 5.82 | 3.97 | 3.76 | - |
| 1990 | - | 5.26 | 7.59 | 7.27 | 5.82 | 4.65 | 3.36 | - |
| 1991 | - | - | - | - | - | 3.13 | - | - |
| 1992 | - | - | - | - | - | - | - | - |
| 1993 | - | - | - | - | - | - | - | - |
| 1994 | - | - | - | - | - | - | - | - |
| 1995 | - | - | - | - | - | - | - | - |
| 1996 | - | - | - | 6.97 | 5.92 | 4.59 | 2.60 | - |
| 1997 | - | - | 5.89 | 7.76 | 7.12 | 4.49 | 3.45 | - |
| 1998 | - | - | - | - | - | 5.39 | - | - |
| 1999 | - | - | - | - | - | - | - | - |
| 2000 | - | 5.41 | - | - | - | - | 0.09 | - |
| 2001 | - | 6.55 | 6.47 | - | 6.74 | 5.59 | 4.38 | - |
| 2002 | - | - | - | - | 5.75 | - | 2.39 | - |
| Average | 4.62 | 5.73 | 6.68 | 7.18 | 6.38 | 4.82 | 2.96 | 2.34 |
University of Illinois Urbana-Champaign- Illinois State Water Survey
- All files and information ©2008
- Last Modified: March 6, 2008