Very large breeds may only have a heat cycle once every 12-18 months. In most giant breeds (Great Danes, Irish Wolfhounds, St Bernard's, etc.) an oestrus cycle every twelve months is common.
Ho Chih Minh City. April is the month with the warmest average high temperature in Ho Chi Ming City. The average high temperature for the month is 95 degrees, and the average low is 79 degrees. December has the lowest temperature on average in Ho Chi Minh City, with an average low temperature of 71 degrees. The average high temperature for December is 89 degrees. No month in Ho Chi Minh City has an average high temperature of less than 89 degrees.
Best time to visit Central Vietnam is during December to March when it is dry and cool. Central Vietnam is affected by the South West monsoon during May to June and torrential rains during November to early December. Tourist peak periods start from January to February. North Vietnam: Hanoi, Halong Bay, Cat Ba Island, Hai Phong, Ninh Binh, Sapa. Best time to visit North Vietnam is during October to March. Winter season starts from November to April with temperature average at a cooling 16 degrees. It can get quite hot from May onwards (Summer season), and a danger of floods due to occasional storms.