SEATTLE TCOMA WSCMO AP, WASHINGTON

Period of Record General Climate Summary - Growing Degree Days

Station:(457473) SEATTLE TCOMA WSCMO AP
From Year=1931 To Year=2006
Growing Degree Days for Selected Base Temperature (F)
Base	Jan.	Feb.	Mar.	Apr.	May	Jun.	Jul.	Aug.	Sep.	Oct.	Nov.	Dec.	Annual
40 M	83	110	172	281	475	611	771	770	611	384	170	85	4523
40 S	83	193	365	647	1121	1732	2503	3273	3884	4268	4438	4523	4523
45 M	23	34	62	141	320	461	616	615	461	234	66	22	3054
45 S	23	57	119	260	580	1041	1657	2272	2733	2967	3032	3054	3054
50 M	3	6	13	49	175	311	461	460	312	105	14	3	1910
50 S	3	8	21	70	245	556	1017	1477	1789	1894	1908	1910	1910
55 M	0	0	1	13	72	168	306	305	170	29	1	0	1065
55 S	0	0	1	15	86	254	561	866	1035	1064	1065	1065	1065
60 M	0	0	0	2	23	65	159	156	63	4	0	0	472
60 S	0	0	0	3	25	90	248	405	468	472	472	472	472

Corn Growing Degree Days
50 M	12	27	56	116	227	322	458	459	327	154	38	11	2204
50 S	12	39	95	211	437	759	1217	1676	2002	2156	2194	2204	2204

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 Jul 28, 2006
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