70 OREGON FARMER 



The mean annual temperature is about 48 degrees. The temperature 

 rises above 90 degrees about 12 different days in the year and reaches 

 the freezing point on about 150 days. There is more rainfall and less 

 sunshine than in the Columbia Basin but the temperatures average 

 lower at the higher altitudes and are subject to greater range. 



Central Oregon. 



The Central Oregon country is mainly a great elevated plain with 

 an average altitude of about 4,000 feet. The summer nights are 

 cool, the rainfall is low and the sunshine abundant. The air is fine 

 and the climate corrective to tuberculosis tendencies and more 

 invigorating than the hot semi-arid sections of the southwestern 

 states. On these plains the growing season is from 65 to 135 days 

 and the rainfall 11 to 14 inches. In the interior part of this region 

 are numerous lakes without any natural outlet and these modify the 

 temperatures of the immediately adjacent lands, so that fruit is 

 produced in favored spots. 



The northern edge of the region is drained by the Deschutes River. 

 This valley averages about 3,000 feet in elevation and has a growing 

 season of ten weeks to four months and a rainfall of about 12 inches 

 in the floor of the valley. Rainfall increases up stream and up the 

 foothills at the sides of the valley. Large areas are irrigated. 



The lower irrigated valley and bench lands of northern Malheur 

 County have a mean elevation of about 2,200 feet and this together 

 with their favorable latitude causes a growing season of five to six 

 months, so the data in the table does not apply. The rainfall is about 

 10 inches. 



In the southwestern part of this region the Lake district has an 

 altitude of about 4,100 feet. At Lakeview and Klamath Falls the 

 growing season is some 130 days. The rainfall at Klamath Falls is 

 13.5 inches, 17 inches at Lakeview and 11 inches at Burns. Large 

 areas tributary to these points are irrigated. 



The Chief Districts Compared. 



The mean monthly and yearly temperatures from selected stations 

 of the Weather Bureau in each of the chief geographic sections of the 

 state are compared graphically in the accompanying diagram (Page 

 69). The bars show an increase in range of temperature as we go to 

 the south and east to higher altitudes and to regions more distant 

 from the ocean. 



The lower bars show the relative amount and distribution of rain- 

 fall for the same stations. The rainfall for La Grande is about 2 . 2 

 inches below average for the district and is misleading in that the 

 average rainfall for the Blue Mountain district is about 2 inches 

 above that of the Columbia Basin. In the western sections of the 

 state the bulk of the rainfall comes between October and March and 

 there is but light rainfall in summer, caused by the shifting of the 

 storm areas and areas of high pressure or clear weather. In Eastern 

 Oregon the maximum rainfall is in winter with a secondary maximum 

 as shown for May and June. 



