CLIMATOLOGY OF THE PERUVIAN ANDES 



131 



before the sea-breeze begins the air is hot and stifling, and 

 dust clouds hover about the traveler. The maximum tempera- 

 ture is attained at this time and not around 2.00 p. m. as is nor- 

 mally the case. Yet so boisterous is the noon wind that the laborers 

 time their siesta by it, and not by the high temperatures of earlier 



OCT.-MARCH 



N N - K 



7 a.m. 



Fig. 81 — Wind roses for Iquique for the summer and winter seasons of the years 

 1911-1913. The diameter of the circle in each case shows the proportion of calm. 

 For source of data see Fig. 80. 



hours. In the afternoon it settles down to a steady, comfortable, 

 and dustless wind, and by nightfall the air is once more calm. 



Of highest importance are the effects of the sea-breeze on pre- 

 cipitation. The bold heights of the Coast Range force the nearly 

 or quite saturated air of the sea-wind to rise abruptly several 

 thousand feet, and the adiabatic cooling creates fog, cloud, and 

 even rain on the seaward slope of the mountains. The actual form 

 and amount of precipitation both here and in the interior region 

 vary greatly, according to local conditions and to season and also 

 from year to year. The coast changes height and contour from 



