Topography

Yemen has a coastline of about 450km and its coastal plain, the Tihamah, averaging 48km in width, is a region of semi-desert. The vast mountain range of the southern Arabian Peninsula runs through the Yemen, with its highest peak, Hadur Shu'ayb at 3,760 metres.
Topographical variations in this region give rise to a wide range of climatic conditions, and its fertile highland plateaux are ideal for growing a wide variety of both tropical and temperate zone crops. These highland regions are interspersed with wadis -- river valleys which are dry in the summer months.
The northern region is rich and fertile, with regular rainfall provided by the effect of the mountains on the Indian Ocean monsoons. Crops include coffee, cotton, sorghum, corn, oats, barley, dates, almonds grapes and qat (a leaf which is widely chewed by Yemeni people). Farming activities also include the breeding of livestock, such as cattle, sheep and goats.
By contrast, only about 2% of the southern region is arable and most farming activity here is confined to the Hadramawt valley. Alluvial deposits along the hot coastal strip running from north to south, make some irrigated farming possible. In the northeastern region of the country, the mountains gradually merge with the Rub al-Khali desert and little agricultural activity beyond herding is possible.
The Yemen was once rich in unique flora and fauna, but little remains of either, as a result of intense cultivation and hunting of wildlife. Indeed, many types of local flora are now endangered and most of the larger wild animals are facing total extinction.

Climate

In the coastal area (the Tihamah region), the climate is primarily dry and hot with an annual rainfall of about 229mm (9in). This region is prone to severe sandstorms and maximum daytime temperatures range from 32°C in winter to over 40°C in summer.
The highland areas boast a mild, temperate climate with pleasantly cool winters. Temperatures range from 21.7°C in June to 13.9°C in January. Highland rainfall varies from about 406mm (16in) to 762mm (30in).
Two periods of increased rainfall are linked with the eastern and western monsoons; the first of these arrives in April/May and the second in July to September. Most of the rain falls on the western mountains. Rainfall gradually diminishes towards the east and in the Rub' al-Khali desert (Empty Quarter) no rain ever falls.