PORTLAND INTL AP, OREGON

Period of Record General Climate Summary - Growing Degree Days

Station:(356751) PORTLAND WSFO
From Year=1941 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 78 119 217 339 540 688 878 882 708 449 197 86 5182
40 S 78 198 415 754 1294 1983 2861 3742 4451 4899 5096 5182 5182
45 M 22 37 91 194 385 538 723 727 558 296 86 25 3682
45 S 22 59 150 343 729 1267 1990 2717 3275 3571 3657 3682 3682
50 M 3 6 23 82 235 389 568 572 408 157 23 4 2470
50 S 3 10 32 114 349 738 1306 1877 2286 2443 2466 2470 2470
55 M 0 0 3 25 113 241 413 417 261 58 3 0 1535
55 S 0 1 3 29 142 383 796 1213 1474 1532 1535 1535 1535
60 M 0 0 0 5 43 115 260 263 131 12 0 0 829
60 S 0 0 0 5 48 163 423 686 817 829 829 829 829
Corn Growing Degree Days
50 M 15 39 92 164 282 392 550 554 419 222 60 16 2804
50 S 15 54 146 309 591 983 1533 2087 2506 2727 2788 2804 2804
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