Passage: Thailand has three seasons. The first is the rainy or southwest monsoon season (mid–May to mid–October) which prevails over most of the country. This season is characterized by abundant rain with August and September being the wettest period of the year. This can occasionally lead to floods. In addition to rainfall caused by the southwest monsoon, the Intertropical Convergence Zone (ITCZ)  and tropical cyclones also contribute to producing heavy rainfall during the rainy season. Nonetheless, dry spells commonly occur for 1 to 2 weeks from June to early July. This is due to the northward movement of the Intertropical Convergence Zone to southern China. Winter or the northeast monsoon starts from mid–October until mid–February. Most of Thailand experiences dry weather during this season with mild temperatures. The exception is the southern parts of Thailand where it receives abundant rainfall, particularly during October to November. Summer or the pre–monsoon season runs from mid–February until mid–May and is characterized by warmer weather.Due to its inland nature and latitude, the north, northeast, central, and eastern parts of Thailand experience a long period of warm weather. During the hottest time of the year (March to May), temperatures usually reach up to 40 °C (104 °F) or more with the exception of coastal areas where sea breezes moderate afternoon temperatures. In contrast, outbreaks of cold air from China can bring colder temperatures; in some cases (particularly the north and northeast) close to or below 0 °C (32 °F). Southern Thailand is characterized by mild weather year-round with less diurnal and seasonal variations in temperatures due to maritime influences.Most of the country receives a mean annual rainfall of 1,200 to 1,600 mm (47 to 63 in). However, certain areas on the windward sides of mountains such as Ranong province in the west coast of southern Thailand and eastern parts of Trat Province receive more than 4,500 mm (180 in) of rainfall per year. The driest areas are on the leeward side...

Question: What is the earliest month of the season where monsoons are frequent?
May