Based on geographic and climatic conditions, there are seven different climatic regions in Vietnam: Northwest, Northeast, North Delta (Red River Delta), North Central (North Central Coast), South Central (South Central Coast), Central Highlands, and the South. The South is subdivided into the Southeast for the southeastern provinces and the Mekong Delta for the southwestern provinces. Generally, these seven different climatic regions are grouped into two main types: The North (includes Northwest, Northeast, North Delta (Red River Delta), North Central (North Central Coast)) which includes all areas north of the Hải Vân Pass and the South (South Central Coast, Central Highlands and the extreme south) which includes all areas south of the Hải Vân Pass. These climatic regions are based on time of rainy season and other climatic elements such as insolation, sunshine, temperature, precipitation, and humidity.