SEATTLE WB CITY, WASHINGTON

Period of Record General Climate Summary - Growing Degree Days

Station:(457488) SEATTLE WB CITY
From Year=1948 To Year=1972
Growing Degree Days for Selected Base Temperature (F)
Base	Jan.	Feb.	Mar.	Apr.	May	Jun.	Jul.	Aug.	Sep.	Oct.	Nov.	Dec.	Annual
40 M	98	148	200	327	532	648	798	788	644	439	233	131	4987
40 S	98	247	447	774	1306	1954	2753	3541	4185	4623	4856	4987	4987
45 M	30	53	76	180	377	498	643	633	494	285	109	41	3420
45 S	30	83	159	339	716	1214	1857	2491	2984	3269	3378	3420	3420
50 M	3	10	17	66	225	348	488	478	344	145	28	6	2160
50 S	3	14	31	97	322	670	1158	1636	1980	2126	2154	2160	2160
55 M	0	1	2	16	102	200	334	323	198	48	2	0	1227
55 S	0	1	3	19	122	322	656	979	1177	1224	1227	1227	1227
60 M	0	0	0	3	34	82	182	171	79	8	0	0	560
60 S	0	0	0	3	37	119	301	472	551	560	560	560	560

Corn Growing Degree Days
50 M	11	31	53	123	252	349	483	476	348	171	52	16	2366
50 S	11	42	95	219	471	819	1303	1779	2127	2298	2350	2366	2366

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