These summaries are based on the Bureau’s HYDRA (Hydrologic Data Retrieval and Alarm) System that records rainfall obtained from rain gages spread across the entire service area and use data from 1977 to 2002 (26 years).

 

Geographic information is based on a representative quarter section for each subwatershed (the quarter section closest to the centroid of the subwatershed) with the rainfall amounts based on the surrounding actual gage data.  In the table below, the winter season extends from November to April, and the summer season extends from May to October.

 

Table: Rainfall by Management Area

Management Area	Quarter Section Number	Winter Average Rainfall (in)	Summer Average Rainfall (in)	Annual Average Rainfall (in)	Winter Maximum Rainfall (in)	Summer Maximum Rainfall (in)	Winter Minimum Rainfall (in)	Summer Minimum Rainfall (in)
Northwest Hills	2421	30.4	10.2	40.6	49.2	15.6	15.9	3.2
Central West Hills	3027	29.9	9.8	39.7	45.4	15.5	14.2	4.1
Southwest Hills	3628	28.3	9.8	38.1	46.2	15.0	15.0	3.5
Northeast Terrace	2021	29.8	10.0	39.9	46.3	16.2	15.2	4.3
Central East Terrace	2934	27.7	9.6	37.3	44.7	15.3	14.3	3.8
Southeast Terrace	3535	28.7	10.1	38.8	44.2	15.3	15.8	4.2
Outer East Terrace	3041	29.4	10.8	40.2	43.5	15.1	15.7	4.6