INTRODUCTION 13 



Dorsale (aleppo pine) from 400 mm. (16 inches) to 600 mm. 

 (23 inches) with 50 to 80 days of rain, while in the southern 

 oases, such as Tozeur, the maximum is 200 mm. (7.8 inches) 

 with perhaps 25 rainy days. 



The distribution of the rainfall is illustrated by the weather 

 records at Zaghouan, bordering the central plateau. A total 

 of 519 mm. (20 inches) for the year, with 73 days of rainfall, 

 showed 28 mm. (1.09 inches) in summer, with only 5 days of 

 rainfall; autumn 121 mm. (4.7 inches) and 18 days of rain; 

 winter 205 mm. (8 inches) and 28 days of rain; spring 165 mm. 

 (6.4 inches) and 22 days of rain. 



The amount of precipitation and number of rainy days for the 

 entire year and for different seasons of the year are as follows: 



TABLE 2 



For the entire Tunisia the average number of rainy days is 

 67 with 537 mm. (22 inches) of rainfall. The average number 

 of rainy days in winter is 43 with 362 mm. (14 inches) of pre- 

 cipitation. In summer the number of rainy days is 24 with 

 175 mm. (6.9 inches) of rainfall. 



In the Sahara region the precipitation nowhere exceeds 

 300 mm. (12 inches). The average temperature is very high. 

 Its maximum reaches 50 C. (122 F.) in the shade. The num- 

 ber of days with temperatures above 30 C. (86 F.) is close to 



These records are taken from the meteorological records at 

 Tunis where they have been collected since 1884. 



