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-Jifārah Plain, the Nafūsah Plateau, and the Akhḍar Mountains. The desert climate of the Sahara reaches the coast along the southern fringes of the Gulf of Sidra, where Al-Ḥamrāyah (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 Benghazi 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 Benghazi 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). Benghazi 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 Sabhā, which averages only 0.4 inch (10 mm) of precipitation annually. Average temperatures at Sabhā 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.

Plant and animal life

In years of ample precipitation, the coastal plains are covered with herbaceous vegetation and annual grasses; the most noticeable plants are the asphodel (an herb of the lily family) and jubule. The northern area of the Akhḍar Mountains—where the influence of the Mediterranean is most dominant—supports low and relatively dense forest (or maquis) of juniper and lentisc. Annual plants are abundant and include brome grass, canary grass, bluegrass, and rye grass. The forest becomes more scattered and stunted south of the mountain crest, and annual plants are less frequent. In the west, plant life is more sparse on the Nafūsah Plateau, where grasslands lie between the barren hills.

In the semiarid steppes, vegetation is also sparse, characterized by pockets of isolated drought-resistant plants. The most commonly found species are saltwort (a plant used in making soda ash) and spurge flax (a shrubby plant), while goosefoot, wormwood, and asphodel also are widespread. Annual grasses grow in the rainy season, and leguminous plants appear in years of good precipitation. Although precipitation is extremely low in the true desert zone and the vegetation cover is scant, some plants from the semiarid region penetrate the occasional wadi valley, and date palms are grown in the southern oases.

Wild animals include desert rodents, such as the desert hare and the jerboa; hyenas; foxes, such as the fennec and the red fox; jackals; skunks; gazelles; and wildcats. The poisonous adder and krait are among the reptiles that inhabit the scattered oases and water holes. Native birds include the wild ringdove, the partridge, the lark, and the prairie hen. Eagles, hawks, and vultures are also common.