ROCK RAPIDS, IOWA

Period of Record General Climate Summary - Growing Degree Days

Station:(137147) ROCK RAPIDS
From Year=1893 To Year=2012
Growing Degree Days for Selected Base Temperature (F)
Base Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. Annual
40 M 1 3 54 247 582 859 1043 966 657 318 49 2 4781
40 S 1 4 58 305 887 1745 2789 3755 4412 4730 4779 4781 4781
45 M 0 1 25 150 433 709 888 811 510 203 19 0 3748
45 S 0 1 25 175 608 1316 2205 3016 3526 3729 3748 3748 3748
50 M 0 0 10 80 296 559 733 656 369 113 5 0 2823
50 S 0 0 10 90 386 945 1678 2334 2704 2817 2823 2823 2823
55 M 0 0 3 38 181 412 578 502 243 54 1 0 2011
55 S 0 0 3 41 221 633 1211 1713 1956 2010 2011 2011 2011
60 M 0 0 1 15 96 273 424 350 141 21 0 0 1320
60 S 0 0 1 16 112 385 809 1158 1299 1320 1320 1320 1320
Corn Growing Degree Days
50 M 1 5 44 167 361 550 691 635 416 212 41 3 3126
50 S 1 6 50 217 577 1128 1819 2454 2870 3082 3123 3126 3126
M = Monthly Data
S - Running sum of monthly data.
Growing Degree Day units are computed as the difference between the daily average temperature and the base temperature. (Daily Ave. Temp. - Base Temp.) One unit is accumulated for each degree Fahrenheit the average temperature is above the base temperature. Negative numbers are discarded. Example: If the days high temperature was 95 and the low temperature was 51, the base 60 heating degree day units is ((95 + 51) / 2) - 60 = 13. This is done for each day of the month and summed.
Corn Growing Degree Day units have the limitations that the maximum daily temperatures greater than 86 F are set to 86 F and minimums less than 50 F are set to 50 F.
Table updated on Oct 31, 2012
Months with 5 or more missing days are not considered
Years with 1 or more missing months are not considered

Western Regional Climate Center, wrcc@dri.edu