This disclosure provides systems, methods, and devices for wireless communication that support relaxed sensing for new radio (NR) sidelink over millimeter wave (mmW) operating frequencies. In a first aspect, a method by a user equipment (UE) of wireless communication includes identifying a resource selection trigger that indicates selection of one or more sidelink slots from a resource selection window. The UE may obtain long-term interference sensing statistics observed by the UE prior to the resource selection trigger. The UE can reduce a default sensing window length in accordance with the long-term interference sensing statistics and transmit a sidelink transmission in the selected sidelink slots. Other aspects and features are also claimed and described.