PORTOLA, CALIFORNIA

Period of Record General Climate Summary - Heating Degree Days

Station:(047085) PORTOLA
From Year=1915 To Year=2012
Heating Degree Days for Selected Base Temperature (F)
Base	Jan.	Feb.	Mar.	Apr.	May	Jun.	Jul.	Aug.	Sep.	Oct.	Nov.	Dec.	Annual
65	1085	900	842	654	461	250	96	136	275	542	803	1039	7083
60	930	759	687	504	311	130	29	48	147	388	653	884	5472
57	837	674	594	415	230	78	11	20	90	299	563	791	4603
55	775	617	532	355	182	53	5	10	62	243	503	729	4067
50	620	476	378	217	86	15	0	1	19	123	354	574	2866

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