SPOKANE INTL AP, WASHINGTON

Period of Record General Climate Summary - Growing Degree Days

Station:(457938) SPOKANE WSO AIRPORT
From Year=1889 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 6 12 69 226 474 663 928 889 589 272 42 9 4180
40 S 6 18 87 313 787 1450 2378 3268 3857 4129 4171 4180 4180
45 M 1 2 20 115 324 513 773 734 441 149 10 1 3083
45 S 1 3 23 138 462 975 1748 2482 2923 3072 3082 3083 3083
50 M 0 0 3 48 191 365 618 580 298 64 1 0 2169
50 S 0 0 4 51 243 607 1226 1805 2103 2167 2169 2169 2169
55 M 0 0 0 16 95 227 464 426 174 21 0 0 1422
55 S 0 0 0 16 111 338 801 1227 1401 1422 1422 1422 1422
60 M 0 0 0 4 38 117 314 279 84 5 0 0 841
60 S 0 0 0 4 42 160 474 752 836 841 841 841 841
Corn Growing Degree Days
50 M 1 4 37 130 271 390 585 558 352 152 11 1 2493
50 S 1 4 41 172 442 833 1418 1976 2328 2480 2491 2493 2493
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