The poleward migration of the ITCZ directly causes: Seasonless for the tropical wet climate A large annual temperature variation for the humid continental climate Long, cold, dark winters and brief, cool summers for the tundra climate Seasonal summer-wet and winter-dry periods for the tropical savanna climate Question 6 The seasonal shift of subtropical highs causes (multiple correct answers): A summer-wet period for the humid subtropical climate A summer-dry period for the Mediterranean climate A winter-dry period for the tropical savanna climate A summer- cool period for the marine west coast climate.