Bangkok, the capital of the Southeast Asian country of Thailand, is influenced by the monsoons, and they are the dominant climatic factor in this region and gives it its climatic patters.
There's two seasons, a wet one, and a dry one. The wet season is characterized by heavy rainfall for a prolonged period of time, and those rains are brought by the wet and warm monsoons coming from east. The dry season is characterized by prolonged period of time that is warm and dry, and that is caused by the dry monsoon winds coming from the west.
During the wet season, the air pressure is higher because the rain increases the weight of the air.
During the dry season, the air pressure is lower because of the high evaporation, and the water vapor is lighter than the air itself, thus causing the air to weigh less.
