It usually occurs in the form of short, heavy showers, and the water scarcely seeps into the ground as much is lost as surface run-off. What ground moisture there is evaporates as a result of the high temperatures. The average temperature in June is between 34 and 38 C. About 15 per cent of the land's surface is covered by mountains with almost no vegetation. About 65 per cent comprises the wide gravel plains of wadis which extend from the mountains or desert to the sea and have thorn and dry savannah vegetation. The remaining area is a broad desert.
Date palms represent the main type of growth in northern Oman.
In the southern province, Dhofar, the coconut palm is dominant. In addition, papayas, bananas, and lemons are grown in oases throughout the country, and grains, fodder, and vegetables of all kinds are planted beneath the trees. Irrigation water comes in most cases from underground falaj systems or from wells. The largest part of the country's surface is unsuitable for agriculture but is the home of a mobile, animal-breeding population. Until 1970 the country was more or less isolated from the outside world and without signs of change but the young Sultan Qaboos, who came to power by way of a bloodless palace revolt on 23 July 1970, introduced policies directed at the modernization of the country.