Below average morning temperatures will allow for patchy frost in wind-sheltered valleys of Riverside and San Diego Counties. For the coastal areas: 40 to 45, western valleys and inland Orange County: 38 to 45, inland valleys: 34 to 43, mountains between 4000 ft and 7000 ft: 22 to 34, high desert: 24 to 32, low desert: 35 to 45.