Libya’s climate is dominated by the hot, arid Sahara, but it is moderated along the coastal littoral by the Mediterranean Sea. The Saharan influence is stronger in summer. From October to March, prevailing westerly winds bring cyclonic storms and rains across northern Libya. A narrow band of semiarid steppe extends inland from the Mediterranean climate of the Al-JifÄ?rah Plain, the NafÅ«sah Plateau, and the Akhá¸ar Mountains. The desert climate of the Sahara reaches the coast along the southern fringes of the Gulf of Sidra, where Al-á¸¤amrÄ?yah (Sirte) Desert borders the sea. Periodic droughts, often lasting several years, are common in the steppe and desert.
Along the coast, the Mediterranean climate is characterized by a cool, rainy winter season and a hot, dry summer. The warmest months are July and August, when average temperatures in BanghÄ?zÄ« and Tripoli, in the Mediterranean zone, reach between the low 70s and mid-80s F (low to upper 20s C) and the low 60s and mid-80s F (upper 10s and low 30s C), respectively. The coolest months are January and February; winter monthly temperatures in BanghÄ?zÄ« range from the low 50s to low 60s F (low to mid-10s C), while those in Tripoli range from the upper 40s to low 60s F (low to mid-10s C). BanghÄ?zÄ« has an average annual precipitation of about 10 inches (250 mm), and Tripoli receives an annual average of about 15 inches (380 mm).
Inland from the coast, annual precipitation declines, and its variability increases. Most rain falls in a few days between November and January. Less than 4 inches (100 mm) of rain falls annually in the steppes, and Saharan zones receive less than 1 inch (25 mm). In the Sahara, 200 consecutive rainless days in a year have been recorded in many areas, and the world’s highest degree of aridity has been recorded at SabhÄ?, which averages only 0.4 inch (10 mm) of precipitation annually. Average temperatures at SabhÄ? are in the low 50s F (low 10s C) in January and in the upper 80s F (low 30s C) in July, but these averages mask the fact that temperatures may vary enormously over the course of a day. The dry climate is exacerbated by the ghibli, a hot, arid wind that blows from the south over the entire country several times a year. It is usually preceded by a short lull in the prevailing winds, followed by the full force of the ghibli. The wind carries large quantities of sand dust, which turns the sky red and reduces visibility to less than 60 feet (18 metres). The heat of the wind is increased by a rapid drop of relative humidity, which can fall dramatically within hours.