Dry desert; hot, humid along coast; hot, dry interior; strong southwest summer monsoon (May to September) in far south.

Most of Oman is desert, yet the history books rarely recall this unimportant two-thirds of the country. Unimportant, that is, until a quarter of a century ago, when suddenly the arrival of the oil companies made the deserts of paramount interest.

The largest part of Oman's desert, running from the Dhahira in the north, down through the Jiddat AI Harasis as far south as Dhofar, does not fulfil the classic idea of a desert at all. It is simply barren land, a vast eige-coloured gravel plain, devoid both of plants and contours. The bedouin who inhabit this inhospitable land are few and far between, their camps not marked by the black tents common in Arabia, but rather consisting of a rough shelter under an acacia tree.

The climate varies from region to region. In the coastal areas it is hot and humid in summer. In the Interior it is hot and dry, with the exception of some higher locations, where it is temperate all year round. In the southern region, the climate is more benign. The country's rainfall is generally low and irregular, although heavy local rains are sometimes experienced, with the exception of the southern region, where heavy monsoon rains regularly occur between June and September.

Only in the extreme east, in the Wahiba, and along the western boaders with SaudiArabia, is the landscape enlivened with classic sand dunes. Along the Saudi border Oman's dunes merge into those of the great sand sea of the Ruba'Al Khali, the Empty Quarter. There too is the sinister salt marsh of Umm As Samim, the "mother of poison". These dangerous quicksands were crossed 40 years ago by Wilfred Thesiger who wrote: "We moved forward a few feet at a time across the greasy surface. Often our weight broke through the surface crust of salt, and then we waded through black, clinging mud which stung the scratches on our legs"