Historical Climate Data

Growing Season Summary
Station: 475364 MERRILL, 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 0 20 149 460 699 848 778 477 190 27 1 3555
GDD
Base 45		 0 0 7 80 319 550 694 624 336 102 9 0 2651
GDD
Base 50		 0 0 2 38 198 404 541 471 212 45 2 0 1862
GDD
Base 55		 0 0 0 17 108 267 388 322 116 17 0 0 1201
GDD
Base 60		 0 0 0 6 50 152 242 185 54 5 0 0 676
MGDD*
Base 50		 0 0 17 113 300 443 547 496 296 124 18 0 2297

*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 5/26 4/29 5/07 6/12 6/21 9/23 8/02 9/07 10/02 10/03
30 5/16 4/25 5/04 6/01 6/11 9/24 9/07 9/13 10/05 10/10
28 5/07 4/22 4/26 5/26 6/11 10/02 9/09 9/19 10/10 10/22
24 4/25 3/25 4/05 5/06 5/12 10/13 9/20 10/01 11/01 11/03
20 4/13 3/25 4/03 4/22 5/06 11/01 9/24 10/10 11/13 11/15
16 4/09 3/15 3/23 4/18 4/22 11/07 10/19 10/22 11/24 11/30

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

Base
Temp
°F		 Median Shortest 10% 90% Longest
32 120 69 93 140 147
30 132 104 112 149 157
28 145 112 126 159 168
24 174 135 153 197 211
20 200 141 177 217 233
16 215 189 195 239 260