SEATTLE WB CITY, WASHINGTON

Period of Record General Climate Summary - Heating Degree Days

Station:(457488) SEATTLE WB CITY
From Year=1948 To Year=1972
Heating Degree Days for Selected Base Temperature (F)
Base	Jan.	Feb.	Mar.	Apr.	May	Jun.	Jul.	Aug.	Sep.	Oct.	Nov.	Dec.	Annual
65	753	575	582	423	251	127	45	41	126	337	527	674	4459
60	598	434	427	275	122	35	4	2	35	190	377	519	3018
57	505	349	334	191	64	9	0	0	11	114	288	426	2292
55	443	294	274	139	35	3	0	0	4	74	229	364	1859
50	291	162	134	38	3	0	0	0	0	17	105	215	965

Heating Degree Day units are computed as the difference between the base temperature and the daily average temperature. (Base Temp. - Daily Ave. Temp.) One unit is accumulated for each degree Fahrenheit the average temperature is below the base temperature. Negative numbers are discarded. Example: If the days high temperature was 65 and the low temperature was 31, the base 50 heating degree day units is 50 - ((65 + 31) / 2) = 2. This is done for each day of the month and summed.
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