SEATTLE WB AIRPORT, WASHINGTON

Period of Record General Climate Summary - Growing Degree Days

Station:(457483) SEATTLE WB AIRPORT
From Year=1948 To Year=1965
Growing Degree Days for Selected Base Temperature (F)
Base	Jan.	Feb.	Mar.	Apr.	May	Jun.	Jul.	Aug.	Sep.	Oct.	Nov.	Dec.	Annual
40 M	80	119	165	317	517	649	805	784	621	408	189	108	4760
40 S	80	199	364	680	1197	1846	2651	3434	4056	4464	4652	4760	4760
45 M	22	38	54	170	362	499	650	629	471	256	80	31	3261
45 S	22	59	113	283	645	1144	1793	2422	2893	3150	3230	3261	3261
50 M	2	6	8	59	211	349	495	474	322	124	17	5	2071
50 S	2	8	16	75	286	636	1130	1604	1926	2049	2067	2071	2071
55 M	0	1	0	13	93	202	340	319	179	39	1	0	1186
55 S	0	1	1	14	107	309	648	967	1146	1185	1186	1186	1186
60 M	0	0	0	1	30	81	187	166	67	6	0	0	540
60 S	0	0	0	1	31	113	300	466	533	539	540	540	540

Corn Growing Degree Days
50 M	14	30	55	140	260	356	489	473	342	177	52	18	2406
50 S	14	43	99	239	499	855	1344	1817	2159	2336	2388	2406	2406

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