ROCK RAPIDS, IOWA

Period of Record General Climate Summary - Heating Degree Days

Station:(137147) ROCK RAPIDS
From Year=1893 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	1555	1281	1017	551	237	47	6	19	163	494	945	1391	7706
60	1400	1140	863	412	136	15	1	3	84	354	795	1236	6438
57	1307	1055	771	333	90	6	0	1	52	279	706	1143	5742
55	1245	999	710	285	65	3	0	0	37	232	646	1081	5302
50	1090	857	562	177	25	0	0	0	13	137	501	926	4288

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