Great Question! In the St Cloud MN area, the appropriate time falls between 4:00 and 11:00 a.m. before the noon sun which evaporates most of your water. This gives the leaf of the plant the opportunity to dry out before going into the night. Leaving your lawn wet at night could lead to a fungal issue where it is staying moist all night long.
Give Emerald Companies (St Cloud MN) a call at 320-251-5296 to speak with someone about an Emerald irrigation system and let us take care of your lawn for the rest of the season.