Hard frost

Hard frost last night along with freezing fog...The low last night at my house was a cold 29.3°...Also had some freezing fog this morning..My road was a little slippery this morning....
Most areas saw frost last night however most areas didn't see a killing frost..I think around my area we did see the killing frost...Seems like points North of HYW 48 was the colder areas..Hayward is reporting a temp of 28°....Get over into my MN forecast area temps are in the lower to middle 20s with a few lower 30s....Will have a forecast later this morning....Will it remain cold or will it warm up ?....I will answer that one later....