In a temperature control unit for a vehicular air conditioning unit including a blast unit and control for the blowoff temperature thereof, a control circuit is provided with a variable gain so that the gain is increased when the blast unit blows air with a high velocity and is decreased when the blast unit blows air with a low velocity whereby a temperature control which does not cause discomfort to a human body may be carried out promptly and automatically. The variable gain of the control circuit may be provided in the form of a feedback loop of the control circuit with at least one of variable resistance or capacitance so as to vary the time constant of the feedback loop and therewith the gain in accordance with the air velocity.