Horses deal with cold temperatures much better than they deal with heat. Provided with adequate supplies of fresh water, hay and feed, horses tolerate sub-freezing, zero or minus temperatures remarkably well. The process of digesting long stem roughage (grass or hay) generates a lot of body heat that keeps horses warm with these cold temps. Snow does not really negatively impact this scenario unless it is particularly wet snow. Rain and wind take away the insulating properties of the horses' hair coat and sap a lot of heat away from them. 33-35 degrees fahrenheit and blowing rain is the hardest weather on livestock. 3 degrees with snow on the ground on a cold winter day is more preferable for horses. Start with a horse in good body condition and keep plenty of good quality feed, hay and water available and short-term blasts of extreme cold are well tolerated.
It is important to encourage the horses to drink enough water during cold weather periods. Some farms will add electrolytes to the feed, a powder made of salt and trace minerals to ensure the horses are well hydrated. Below Alpine Sky at Old Tavern Farm takes in the winter weather.