Geography of Oman - Climate

Climate

With the exception of Dhofar region, which has a strong monsoon climate and receives warm winds from the Indian Ocean, the climate of Oman is extremely hot and dry most of the year.

Summer begins in mid-April and lasts until October. The highest temperatures are registered in the interior, where readings of more than 53 °C (127.4 °F) in the shade are common. On the Al Batinah plain, summer temperatures seldom exceed 47 °C (116.6 °F), but, because of the low elevation, the humidity may be as high as 90 percent. The mean summer temperature in Muscat is 33 °C (91.4 °F), but the gharbi (literally, western), a strong wind that blows from the Rub al Khali, can raise temperatures from the towns on the Gulf of Oman by 6 °C (10.8 °F) to 10 °C (18 °F).

Winter temperatures are mild and pleasant, ranging between 18 and 26 °C (64.4 and 78.8 °F).

Precipitation on the coasts and on the interior plains ranges from 20 to 100 millimeters (0.8 to 3.9 in) a year and falls during mid- and late winter. Rainfall in the mountains, particularly over Jebel Akhdar, is much higher and may reach 900 millimeters (35.4 in).

Because the plateau of Jebel Akhdar is porous limestone, rainfall seeps quickly through it, and the vegetation, which might be expected to be more lush, is meager. However, a huge reservoir under the plateau provides springs for low-lying areas. In addition, an enormous wadi channels water to these valleys, making the area agriculturally productive in years of good rainfall.

Dhofar, benefiting from a southwest monsoon between June and September, receives heavier rainfall and has constantly running streams, which make the region Oman's most fertile area.

Occasionally, a cyclone from the North Indian Ocean makes landfall, bringing with it heavy rain, such as Cyclone Kelia did in 2011. Oman was hit by Cyclone Gonu on June 6. Large areas in the capital area region in the Governorate of Muscat and in Amerat and Quriyat were severely affected. Gonu first hit the southern city of Sur late on June 5, 2007. Oman is one of the few countries with no National Red Crescent or Red Cross Society.