Climate in Kerala. The year may be divided into four seasons. The period March to the end of May is the hot season. This is followed by South West Monsoon Season that continues till the beginning of October. From October to December is the North East Monsoon Season and the two months of January and February, winter season. Summer months March to May are uncomfortable due to high temperature humidity. The State is extremely humid due to the existence of Arabian Sea in the west of it. While most of the areas are under tropical dry and wet conditions with high maritime influence, certain areas in the eastern parts experience sub-tropical type of climate.