 And to that end, there is a heat advisory that will kick into effect later this morning, beginning at 10 a.m. throughout the Delmarva Peninsula in southern New Jersey. Now, it depends on where you are as to how long that heat advisory goes until. For instance, in the first state, Maryland's mid and upper shore, the heat advisory kicks in at 10 a.m. and runs until 8 o'clock tomorrow night.