In the state of Utah scarcely a year passes without some damage being done to farm crops, either in the spring or the fall, because of the occurrence of killing frosts. For example, in the spring of 1916 the tops of the young beets were frozen, about one-fourth of the grain of the northern part of the state was frozen, the yield of the first crop of alfalfa was about half normal and 90 per cent of the fruit of the state was destroyed. During the month when fruit buds are in bloom, the report of the U. S. Weather Bureau shows that on an average covering ten years for the five leading horticultural counties, freezing temperatures of 30 degrees, or below, are experienced six nights a year. The county agricultural agents report that three years out of ten the fruit crop is somewhat below normal due to frost, that the crop is considerably below normal one year out of ten for the counties, and that certain orchards in the counties frequently lose their entire crop.
West, Frank L. and Edlefsen, N. E., "Bulletin No. 161 - Orchard Heating" (1917). UAES Bulletins. Paper 127.