CIRCLE, MONTANA

Period of Record General Climate Summary - Growing Degree Days

Station:(241758) CIRCLE
From Year=1963 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	1	7	42	195	470	726	962	923	546	237	36	3	4149
40 S	1	8	50	245	715	1441	2404	3326	3873	4110	4146	4149	4149
45 M	0	1	14	108	329	576	807	768	405	138	12	0	3159
45 S	0	1	15	123	452	1028	1835	2603	3009	3146	3159	3159	3159
50 M	0	0	3	52	206	428	652	613	275	68	3	0	2300
50 S	0	0	4	55	262	689	1342	1955	2230	2297	2300	2300	2300
55 M	0	0	1	19	111	286	498	461	167	27	1	0	1570
55 S	0	0	1	20	131	418	916	1376	1543	1570	1570	1570	1570
60 M	0	0	0	5	50	167	347	316	88	8	0	0	981
60 S	0	0	0	5	55	222	570	885	974	981	981	981	981

Corn Growing Degree Days
50 M	2	8	44	149	299	450	607	580	354	181	36	4	2714
50 S	2	10	54	203	502	952	1559	2139	2494	2674	2710	2714	2714

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