12 in accordance with the present average amount of arable land per farm, 180 acres, as shown by the Census, would be sufficient to create 3,400 new farms which would give a total of 4,600 farms in the area. Climate The climate of the area is of the interior continental type which is character- ised by a relatively low rainfall and extremes of seasonal temperatures. In the study area, however, the low rainfall is associated with a relatively high pre- cipitation efficiency. For that reason complete crop failures because of drought are almost unknown, although variations in crop yields occur from year to year because of lack of moisture during the growing season. Average summer temperatures are similar to those of the northernmost settled areas in the Prairie Provinces. Within the area, however, the physical features cause local climatic varia- tions to occur. Particularly significant to agricultural development are the differences in length of the frost-free period. That period has been found to differ markedly between contiguous parcels of land, due chiefly to altitude differences and locations with respect to air drainage. Rainfall and average temperatures during the growing seasons also vary but tend to do so over more extensive areas. Data available from weather station records show that the Prince George district has the highest seasonal precipitation and also higher summer temperatures than other parts of the area. Precipitation.—The precipitation for the growing season, May to August inclusive has the most significance with respect to crop production. For this period the long-time average was 7-5 inches at Prince George and 5-0 to 5-6 inches at other weather stations located in the western portions of the area (Table 2). TABLE 2.—PRECIPITATION! AND PRECIPITATION EFFICIENCY? RECORDED AT VARIOUS STATIONS, PRINCE GEORGE-SMITHERS AREA Num- oe eae = é 3 Annual Precipitation | Precipitation Weather Station ber of Precipitation |May 1-Aug. 31} Efficiency | Years inches inches percent ‘Prince:George nee oe ee a ee ee eee ee 31 21-0 7-5 59 Fort St. James st 51 15-6 5-6 55 Wistaria.... 18 17-6 5-0 57 Delkowa st ecen coon perc ee eee 22 15-4 5-6 45 Maclure: Lake ta. cosa wee ei eee 30 15 2 5-0 um Vand er hook as. orc ero tee een |e een | en nee UNL pn ae eel 39 1 Climate of British Columbia, 1944, Province of British Columbia, Department of Agriculture. 2 Unpublished data, Agronomy Department, University of British Columbia. Precipitation efficiency, however, is not necessarily associated with high rainfall. The efficiencies calculated for Prince George and Wistaria were similar, being 59 and 57 per cent, respectively, in spite of the lower rainfall at the latter point. Telkwa and Vanderhoof were definitely drier areas, with precipitation efficiencies of 45 and 39 per cent, respectively. Summer Temperatures.—The average temperatures for the summer months of June, July and August have been recorded as 58° F. at Prince George and 55° F. at the other weather stations within the area (Table 3). The low summer temperatures partly accounted for the relatively high moisture efficiency of the area as compared with moisture efficiencies calculated for other points in the province farther south but with similar rainfall.