Yemen overlooks two seas, the Red Sea and the Arab Sea. However, Yemen's climate didn’t benefit a lot from the marine characteristics significantly only in raising the air humidity in the coasts. Influence of these two seas in modifying the republic's climate features is very limited. Rather it is confined to humidity and modifying the wind features while their effect in the air instability is limited. Rain falls in two seasons. The first season during the spring season (March- April) and the second season in the summer (July- August) during which rains fall greater than the spring season. The amount of rainfall varies greatly from a place to a place. The highest amount of annual rainfall is on the south west highlands as in Ibb, Taiz, Aldhale'a and Yareem. The amount of rainfall ranges between 600-1500m annually. The amount of rainfalls in the western coastal plain become less as in Hodeidah, Mokha, despite the exposure to the monsoon south-west from the Indian Ocean crossing the Red Sea as a result of the absence of a factor raising the wind humid However, the average rainfall annual increases with the altitude of 50 mm on the coast to about 100 0 mm on the slopes of the mountains facing the Red Sea.
The same can be said about the country's southern and eastern coasts as has been said about the western coasts regarding the rainfall amounts that reach around 50mm per annual as in Aden, Alfayoush, Alkud and Alrayan. This can be attributed to many factors, the main one of which is that the direction of the humid wind movement runs parallel with the coast without penetrating into the internal parts; therefore, the impact would be very small and hence the rainfall are of no economic significance whatsoever.
As for temperature, the eastern and southern plains has such high temperature degrees that it reaches 42°m and goes down to 25°m. Temperature goes down gradually toward higher elevations because of the height factor to reach 33°m as a maximum and 20°m as a minimum. In winter the lesser temperature on the highlands reaches closer to Zero degree and in Dhamar Governorate, in the winter, the temperature -12°m was recorded in 1986.
As for humidity, it is high on the coastal plains up to more than 80% whereas it goes down toward the internal parts where it reaches its minimum rate in the desert areas around 15%.