Historical Climate Data

Growing Season Summary
Station: 476718 PORTAGE, WI

Growing Degree Day Averages
Derived from 1971-2000 Data

 

Element JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC ANN
GDD
Base 40		 0 5 58 240 568 820 975 906 625 305 62 6 4568
GDD
Base 45		 0 1 29 143 417 670 820 751 478 187 27 2 3521
GDD
Base 50		 0 0 13 77 279 520 665 596 337 101 9 0 2593
GDD
Base 55		 0 0 5 37 166 374 510 442 213 46 2 0 1792
GDD
Base 60		 0 0 1 16 85 239 357 293 118 16 0 0 1123
MGDD*
Base 50		 0 4 40 158 355 534 650 598 393 189 35 3 2958

*Modified Growing Degree Days: Base 50 Ceiling 86.

Growing Season Summary
Derived from 1971-2000 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 5/07 4/07 4/18 5/26 6/12 9/30 9/04 9/17 10/11 10/17
30 5/01 4/03 4/11 5/23 6/12 10/03 9/20 9/21 10/20 11/10
28 4/20 3/24 4/03 5/13 5/27 10/07 9/22 9/22 11/03 11/10
24 4/14 3/22 3/30 5/03 5/09 10/22 9/22 10/07 11/12 11/15
20 4/06 3/06 3/18 4/16 4/26 11/04 9/22 10/19 11/22 12/21
16 3/24 2/18 3/10 4/09 4/18 11/12 10/18 10/22 12/01 12/21

Length of Growing Season (Days)
Derived from 1971-2000 Averages

Base
Temp
°F		 Median Shortest 10% 90% Longest
32 151 111 117 171 184
30 160 111 122 187 202
28 174 129 135 211 216
24 200 139 159 222 236
20 214 167 186 247 279
16 230 194 205 268 279