Historical Climate Data

Growing Season Summary
Station: 476939 RAINBOW RESERVOIR, WI

Growing Degree Day Averages
Derived from 1971-1996 Data

Element JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN
GDD
Base 40		 0 0 10 98 385 628 785 731 434 161 18 0 3219
GDD
Base 45		 0 0 3 51 254 479 630 576 293 83 5 0 2350
GDD
Base 50		 0 0 0 23 152 334 475 422 177 35 1 0 1604
GDD
Base 55		 0 0 0 10 81 206 322 273 91 12 0 0 985
GDD
Base 60		 0 0 0 3 36 105 183 146 40 3 0 0 511
MGDD*
Base 50		 0 0 10 87 261 386 491 451 254 103 12 0 2037

*Modified Growing Degree Days: Base 50 Ceiling 86.

Growing Season Summary
Derived from 1971-1996 Averages

  Date of Last Spring Occurrence Date of First Fall Occurrence
Base
Temp
°F		 Median Early 90% 10% Late Median Early 90% 10% Late
32 5/27 5/09 5/13 6/11 6/22 9/23 9/03 9/13 10/02 10/04
30 5/24 5/07 5/10 6/03 6/23 9/25 9/20 9/22 10/08 10/09
28 5/13 4/18 4/26 5/27 6/22 10/03 9/20 9/23 10/12 10/21
24 5/03 4/08 4/13 5/09 5/14 10/13 9/23 9/27 11/03 11/12
20 4/21 4/04 4/09 5/02 5/07 11/01 10/09 10/13 11/12 11/16
16 4/13 4/01 4/05 4/22 4/26 11/05 10/19 10/24 11/16 11/16

Length of Growing Season (Days)
Derived from 1971-1996 Averages

Base
Temp
°F		 Median Shortest 10% 90% Longest
32 120 89 104 133 135
30 126 93 114 139 151
28 143 94 131 160 166
24 166 139 145 183 187
20 194 155 174 207 217
16 206 176 191 217 222