Historical Climate Data

Growing Season Summary
Station: 478349 SUPERIOR, 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 1 8 70 295 554 808 779 507 199 22 0 3127
GDD
Base 45		 0 0 1 29 171 405 655 625 361 99 6 0 2264
GDD
Base 50		 0 0 0 10 88 265 502 471 226 39 1 0 1539
GDD
Base 55		 0 0 0 2 40 151 351 320 120 11 0 0 954
GDD
Base 60		 0 0 0 0 14 72 214 185 52 2 0 0 516
MGDD*
Base 50		 0 1 6 49 157 303 499 477 277 97 11 0 1810

*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 5/12 4/16 4/26 5/26 6/05 9/29 9/19 9/21 10/16 11/03
30 5/06 4/13 4/21 5/24 6/05 10/03 9/20 9/23 10/23 11/04
28 4/29 4/07 4/21 5/13 6/05 10/08 9/22 9/26 11/01 11/04
24 4/19 3/24 4/05 5/04 6/05 10/29 9/24 10/06 11/08 11/16
20 4/06 3/17 3/24 4/20 5/19 11/03 10/02 10/17 11/15 11/21
16 4/05 2/27 3/11 4/20 5/19 11/11 10/20 10/28 11/25 12/19

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

Base
Temp
°F		 Median Shortest 10% 90% Longest
32 143 109 127 159 189
30 154 109 136 175 190
28 164 109 149 186 193
24 188 151 163 208 233
20 213 169 182 227 246
16 221 194 201 249 274