CEREAL INVESTIGATIONS ON THE BELLE FOURCHE FARM. 



9 



about 60 miles north and 30 miles west of Newell. Aberdeen is 

 directly east of Camp Crook, but is about 90 miles from the eastern 

 boundary. Pierre is on the Missouri River in the central portion of 

 the State. Brookings is in the same latitude as Pierre, but within 20 

 miles of the eastern boundary. 



Table VII. — Mean monthly and annual temperatures at Newell, Camp Crook, Aberdeen, 

 Pierre, and Brookings, S. Dak., for the periods indicated. 



[Data (in °F.) for Newell from the records of the Biophysical Laboratory of the Bureau of Plant Industry 

 and for other stations from the records of the United States Weather Bureau.] 



Months. 



January 



February 



March 



April 



May , 



June 



July 



August 



September... 



October 



November. . . 

 December. .. 



Annual 



Newell. 



6 years 



dun's iui:i). 



H5.0 

 19.0 

 31.8 

 45.8 

 53.7 

 67.0 

 71.7 

 69.7 

 59.0 

 45.3 

 33.2 

 21.3 



44.4 



Camp 

 Crook. 



20 years 

 (1894-1913) 



17.7 

 18.9 

 28.2 

 43.9 

 54.1 

 63.2 

 69.5 

 68.7 

 58.6 

 45.6 

 31.3 

 23.7 



43.6 



Aberdeen. 



23 years 

 (1891-1913). 



9.6 

 11.2 

 26.2 

 44.8 

 55.9 

 66.1 

 70.9 

 68.7 

 59.0 

 45.7 

 28.8 

 16.9 



Pierre. 



21 years 

 (1893-1913) 



14.1 

 16.9 

 29.4 

 46.7 

 59.1 

 69.1 

 75.2 

 73.3 

 62.9 

 48.9 

 32.0 

 20.5 



45.7 



Brookings. 



24 years 

 (1890-1913). 



12.2 

 13.8 

 28.5 

 45.0 

 55.2 

 65.1 

 69.6 

 67.9 

 59.7 

 46.3 

 29.5 

 19.6 



42.7 



a For five years only. 



The record of mean temperatures at Newell is for a much shorter 

 period than the records for the other localities noted in Table VII, 

 so that the figures are not entirely comparable. The annual mean 

 and monthly mean temperatures at Newell differ only slightly from 

 those at Camp Crook. 



The annual mean temperatures in western South Dakota are shown 

 to be slightly higher than those in the eastern part of the State. The 

 difference between the mean temperature at Camp Crook and at 

 Aberdeen is 1.6 degrees, while that of Pierre is 3 degrees higher than 

 that of Brookings. The variation between the Brookings and Pierre 

 temperatures is quite constant throughout the year, but most of the 

 variation between the Camp Crook and Aberdeen temperatures oc- 

 curs in December, January, and February. The average of the 

 mean temperatures for these three months is 7.9 degrees lower at 

 Aberdeen. This variation in winter temperatures perhaps accounts 

 for the fact that winter wheat is more likely to winterkill in eastern 

 than in western South Dakota. 



Table VIII gives the dates of the last spring and first fall frosts 

 and the number of days in the frost-free period during each year from 

 1908 to 1913, inclusive. The latest date on which frost has occurred 

 in the spring during the six years was May 23, and the average date 



