Rub al-Khali recieves almost no rain at all. Mountain peaks rise to 3,000 meters and there is a lot of rainfall to support natural vegetation and cultivation. Asir, with some juniper trees, wild olive trees and even some larger trees is the only part of the Kingdom of Saudi Arabia to support forest. The Southern Region has always been densely populated. With the implementation of government irrigation schemes, the agricultural potential of the region is being increasingly exploited.
Temperatures remain within a narrower band than is the case in many other parts of the Kingdom.
The Abha region also enjoys the highest level of rainfall of any part of Saudi Arabia. The natural beauty of the region and its fertility have encouraged the Saudi Arabian Government to establish a number of national parks, enabling Saudi citizens to holiday in a location of outstanding scenery and natural interest to rival anywhere abroad. The Red Sea port of Jeddah is located on the ancient trade routes and its status as the seaport and airport for hajjis, visiting the Holy City of Makkah, have ensured that Jeddah is the most cosmopolitan of all Saudi Arabia's cities. By the end of the 1970's the population of Jeddah was estimated to be close to 1 million. By 1986, the estimated population was 1.4 million.