Summertime in Minnesota can get pretty warm and we are approaching the warmest part of the summer. Daytime highs in the 90 degree range and above are not uncommon. Since we have a lot of dairy farms in Minnesota, we have to be aware of what it takes to keep cows comfortable and producing during the warm summer months. Why the concern? Dairy cows are most productive at temperatures between 41 and 77 degrees F. At temperatures above 77 degrees, cows begin to use energy to rid themselves of heat generated by digestion and metabolism energy that could be used to produce milk or grow a calf if pregnant. As relative humidity increases at temperatures above 77 degrees F, the combined heat and humidity increases the heat stress that cows experience.