PORTOLA, CALIFORNIA

Period of Record General Climate Summary - Growing Degree Days

Station:(047085) PORTOLA
From Year=1915 To Year=2012
Growing Degree Days for Selected Base Temperature (F)
Base	Jan.	Feb.	Mar.	Apr.	May	Jun.	Jul.	Aug.	Sep.	Oct.	Nov.	Dec.	Annual
40 M	5	13	52	140	322	509	727	669	480	248	54	9	3227
40 S	5	18	70	210	531	1040	1767	2437	2916	3164	3218	3227	3227
45 M	0	1	12	55	190	362	572	514	333	127	12	1	2181
45 S	0	2	14	69	259	621	1193	1707	2040	2168	2180	2181	2181
50 M	0	0	1	13	90	224	417	360	198	47	1	0	1352
50 S	0	0	1	14	104	329	746	1106	1304	1351	1352	1352	1352
55 M	0	0	0	1	31	112	267	214	91	11	0	0	727
55 S	0	0	0	1	32	144	410	625	715	727	727	727	727
60 M	0	0	0	0	6	39	136	97	26	2	0	0	306
60 S	0	0	0	0	6	45	181	278	304	306	306	306	306

Corn Growing Degree Days
50 M	15	28	79	155	276	391	523	509	412	268	92	20	2768
50 S	15	43	122	277	553	944	1468	1976	2388	2656	2748	2768	2768

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 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