CAIRO 3 N, ILLINOIS

Period of Record General Climate Summary - Heating Degree Days

Station:(111166) CAIRO 3 N
From Year=1948 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	937	731	524	213	47	2	0	0	24	194	502	827	4000
60	783	591	383	121	14	0	0	0	7	103	364	674	3039
57	692	509	307	80	5	0	0	0	2	63	288	583	2530
55	632	456	259	58	2	0	0	0	1	43	242	525	2217
50	486	330	158	22	0	0	0	0	0	13	144	384	1537

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