THE DESERT CLIMATE 



17 



acteristic. Almost any place in any desert will 

 show these essential characteristics of the desert 

 climate, provided it is not close to the sea. 



The contrast between a hot summer and a cold 

 winter is shown not only by mean figures, such as 

 those on which Fig. 5 is based, but even better by 

 quoting the extremes of temperature which have 

 been recorded at a given spot either in one year or 

 in a series of years. The following are good 

 examples : 



The following figures from Wadi Haifa (Anglo- 

 Egyptian Sudan) are interesting because they show 

 that though the normal range of temperature is 

 great the occasional range is very much greater : 

 the coldest month is January, with a mean lowest 

 reading of 7-8° C. (46° F.); the absolute lowest 

 reading in twenty-one years was — 2-2° C. (28° 

 R); the mean highest reading is 41-1° C. (106° F.) 

 (June), the absolute highest being 52-5° C. (130° F.) 

 in April. It is clear that a slight frost, occur- 

 ring once in a score of years, at a place in which 

 the thermometer does not pass below 7-8° C. 



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