Arabia receives little rain and has no permanent rivers. Much of Arabia is covered by desert. Summer temperatures can soar to more than 120 degrees Fahrenheit. The harsh environment helped keep large populations out of Arabia for most of its history.
Arabia's climate shaped its population. The people depended on oases (oh AY seez) for water. An oasis is a place in a desert where water can be found, usually from a spring. Most early settlements occurred around oases in the Hijaz, a mountainous region along the western coast of Arabia.