Historical Climate Data

Growing Season Summary
Station: 478919 WATERTOWN, 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		 1 5 60 236 581 846 1006 935 658 336 75 7 4749
GDD
Base 45		 0 1 29 137 430 696 851 780 510 211 36 2 3688
GDD
Base 50		 0 0 13 73 291 547 696 625 366 118 14 0 2746
GDD
Base 55		 0 0 5 35 174 400 541 471 235 55 4 0 1924
GDD
Base 60		 0 0 1 16 93 261 387 318 133 21 0 0 1234
MGDD*
Base 50		 0 3 36 143 351 546 676 617 405 193 38 3 3015

*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 4/28 4/08 4/13 5/11 5/27 10/06 9/22 9/23 10/17 10/22
30 4/21 4/08 4/09 5/06 5/09 10/09 9/22 9/26 11/02 11/09
28 4/17 3/26 4/05 5/03 5/09 10/19 9/22 10/04 11/05 11/15
24 4/09 3/17 3/26 4/18 4/22 11/04 10/02 10/16 11/18 12/01
20 3/29 3/07 3/13 4/11 4/15 11/12 10/19 10/22 11/28 12/08
16 3/22 2/21 3/02 4/07 4/14 11/22 10/31 11/08 12/10 12/21

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

Base
Temp
°F		 Median Shortest 10% 90% Longest
32 162 136 138 180 189
30 175 138 151 195 213
28 187 149 158 211 221
24 211 177 188 229 249
20 227 192 202 255 266
16 251 217 219 280 284