North Thailand weather - three seasons

In northern Thailand the seasons are clearly defined. Between November and June the weather is mostly dry, however, this is broken up into the periods November to February and March to May. Although the NE monsoon does not directly effect the northern area of Thailand, it does cause cooling breezes from November to February. During the cool season in the north it can get quite chilly at night. The hot season is between March and June. The other northern season is from June to November and is dominated by the southwest monsoon, during which time rainfall in the north is at its heaviest.