PORTOLA, CALIFORNIA

Period of Record General Climate Summary - Growing Degree Days

Station:(047085) PORTOLA
From Year=1948 To Year=2006
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	15	49	137	326	519	734	691	503	272	57	9	3316
40 S	5	19	68	205	532	1051	1785	2475	2979	3250	3307	3316	3316
45 M	0	2	11	53	194	372	579	536	356	144	12	1	2260
45 S	0	2	13	66	260	632	1211	1747	2103	2247	2259	2260	2260
50 M	0	0	1	12	94	233	425	381	217	56	1	0	1419
50 S	0	0	1	13	107	340	765	1146	1363	1418	1419	1419	1419
55 M	0	0	0	1	33	116	273	231	102	14	0	0	770
55 S	0	0	0	1	34	151	424	655	757	770	770	770	770
60 M	0	0	0	0	7	41	138	105	30	1	0	0	323
60 S	0	0	0	0	7	47	186	291	322	323	323	323	323

Corn Growing Degree Days
50 M	10	29	69	148	271	392	522	509	415	276	82	15	2739
50 S	10	39	108	256	527	919	1441	1950	2365	2641	2724	2739	2739

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