MERWIN DAM, WASHINGTON

Period of Record General Climate Summary - Heating Degree Days

Station:(450242) ARIEL DAM
From Year=1930 To Year=1971
Heating Degree Days for Selected Base Temperature (F)
Base	Jan.	Feb.	Mar.	Apr.	May	Jun.	Jul.	Aug.	Sep.	Oct.	Nov.	Dec.	Annual
65	785	-99	-99	394	303	150	86	-99	128	385	661	745	-99
60	630	-99	-99	247	169	58	23	-99	54	250	511	590	-99
57	537	-99	-99	166	106	23	3	-99	27	187	421	497	-99
55	475	-99	-99	115	70	11	0	-99	16	147	361	435	-99
50	320	-99	-99	28	18	0	0	-99	6	62	212	293	-99

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 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