LEWISTOWN FAA AP, MONTANA

Period of Record General Climate Summary - Cooling Degree Days

Station:(244985) LEWISTOWN FAA AP
From Year=1896 To Year=2006
Cooling Degree Days for Selected Base Temperature (F)
Base	Jan.	Feb.	Mar.	Apr.	May	Jun.	Jul.	Aug.	Sep.	Oct.	Nov.	Dec.	Annual
55	0	0	1	7	44	138	329	297	99	18	1	0	933
57	0	0	1	4	29	102	271	242	71	10	0	0	730
60	0	0	0	1	14	60	191	166	39	4	0	0	476
65	0	0	0	0	3	19	85	70	11	0	0	0	189
70	0	0	0	0	0	4	24	18	1	0	0	0	48

Cooling 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.
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