16 U.S. NATIONAL MUSEUM BULLETIN 275 



belt between it and the humid climate of the Mediterranean littoral. 

 These steppe areas in Libya are located on the margins of the trade 

 winds and subtropical highs and are hence nearer to the humid climates. 

 These areas are subjected to brief periods of winter, rain-bearing winds 

 and their associated storms (the westerlies and their cyclonic storms), 

 which cause them to be semiarid rather than arid. 



At Benghazi, near the northern limits of the steppe region of 

 Cyrenaica, no rainfall occurs during the months of June, July, and 

 August, while December and January receive moderate amounts of 

 rain. The steppe thus has almost all of its rain in the winter; the 

 yearly total is 11.9 inches. The amount of precipitation varies from 

 year to year from a recorded high of 24.3 inches to a low of 6.8 inches. 

 Variability of rainfall is as great in the steppe region as in the true 

 Saharan region. Because rain falls in showers of comparatively short 

 duration, the weather is prevailingly sunny. 



Mediterranean Littoral 



Most portions of coastal Libya have a Mediterranean or dry-summer 

 subtropical climate. This climate, according to Trewartha, is character- 

 ized by three principal features: most precipitation in the winter 

 season; warm to extremely hot summers and mild winters; and a 

 high percentage of sunshine for the year, especially in the summer. 



This Mediterranean climate in coastal Libya results from the 

 dought-producing dry subtropical highs and tradelike winds on the 

 south and the humid westerlies with their cyclonic storms on the north. 

 As a result of the north-south shifting of these wind belts, these 

 Mediterranean latitudes are joined at one season to the dry tropics 

 and at the opposite season to the humid middle latitudes. 



A uniform summer and a variable winter climate characterize these 

 coastal areas. The climate of coastal Libya is transitional between 

 the low-latitude steppe and desert and the cool, humid climates 

 farther poleward. 



It is the relative warmth of the Mediterranean Sea in winter, and 

 the resulting low-pressure trough coincident with it, that attracts 

 cyclonic storms in the winter season. The Mediterranean climate of 

 coastal Libya is thus assured of a temperature regimen in which 

 cold weather is largely absent. Winter months have average tempera- 

 tures of between 40° F and 50° F, and the summer months between 

 70° F and 80° F, and mean annual ranges of 20° to 30° F are common. 

 At Tobruch, on the northeastern Cyrenaican coast, the average 

 January temperature is 56° F, while the average for July is 79° F. 

 The average annual temperature at Benghazi on the coastal plain on 

 on the Gulf of Sirte is 69° F with averages of 55° in January and 79° 

 in August. 



