THE CLIMATE OF LOURENc^O MAROUES. 307 



in these climates, owing to their bad consec(iiences, also lends 

 importance to the knowledge of temperature extremes. 



An examination of the absolute maxima and minima shown 

 in Table No. IV gives one an unfavourable impression, but these 

 extreme variations are due to the hot zviiids from NNW that 

 precede atmospheric depressions, and are immediately followed 

 by fresh v^outh Wind which causes great decreases of tempera- 

 ture, these being at times as much as i6° C. (28.8° F.) within 

 one and a half hour. 



This undoubtedly important circumstance is common to the 

 whole South African Coast, from Walfisch Bay to Durban. 



From the observations of three complete years I have 0I1- 

 tained the following data : — 



Maximum temperature higher than 35° C. (95° F.) 



was registered 21 times. 



Maximiim temperature higher than 40° C. (104'' F. ) 5 

 Mininium temperature between 9° and 10° C. (48.2° 



and 50° F.) 21 



Minimum temperature between 8° and 9"^ C. (4(^.4° 



and 48.2° F.) 6 .. 



Minimum temperature between j° and 8° C. (44.6° 



and 46.4° F. ) once. 



Minimum temperature equal to 25° C. (/y" F. ) . . once. 



■\rinmum temperature between 24° and 2=^° C. (75.2° 



and '/■/° F.) 8 times. 



Minimum temperature Ijetween 2t,° and 24° C. 



(73.4° and 75.2° F.) 26 .. 



\'ariation of temperature on the same day,. 25.8° C. 



(46.4° F.) once. 



Variation of temperature on the same day between 



20° and 25° C. (36° and 45.5° F.) 17 times. 



\'ariation of temperature on the same day between 



15° and 20° C. {27° and 36.4° F.) . .' 67 .. 



Thus temperature higher than 40° C. (104" F. ) and lower 

 than 9° C. (48.2° F.) may be considered exceptional, and the 

 same can be said of variations in one day higher than 20' C. 

 (36° F.). 



Similarly, one concludes that the minimum daily temperature 

 is rarely higher than 24° C. (75.2° F.), very seldom above 23" C. 

 (73.4° F.), and for this reason the heat at night is not, as a rule, 

 very troublesome. 



I am therefore of opinion that these extreme temperatures 

 and high variations in one day should not have a very unfavour- 

 able result, owing to their rare occurrence. It should also be 

 noted that temperatures above 40° C. (104° F.) are registered 

 in temperate climates, such as Lisbon and in France, where the 

 minima are far below those obtaining here. 



I shall refer again to this NNW hot zvi}id that has always 



B 



