138 



Redding — the mean annual temperature is 64.14 degrees. 



Red Bluff — the mean annual temperature is 66. 22 degrees. 



Chico — the mean annual temperature is 62.46 degrees. 



Marvsville — the mean annual temperature is 63.62 degrees. 



Sacramento — the mean annual temperature is 60.48 degrees. 



Stockton — the mean annual temperature is 61.99 degrees. 



Modesto — the mean annual temperature is 63.68 degrees. 



Merced — the mean annual temperature is 63.16 degrees. 



Borden — the mean annual temperature is 66.37 degrees. 



Tulare — the mean annual temperature is 64.09 degrees. 



Delano — the mean annual temperature is 68.64 degrees. 



Sumner — the mean annual temperature is 68.29 degrees. 



It will be seen that (for the year) Sacramento is the coolest place 

 in the valley, the temperature increasing both north and south from 

 this point. The breeze from the ocean in summer follows up the river 

 and reaches Sacramento each day about five p. m., and thus reduces the 

 mean of its temperature. It may be from the same influence that 

 its rainfall is increased above the next stations north and south. 

 The reduction of temperature at Sacramento by the air from the 

 ocean passing through the Golden Gate and up the Sacramento 

 River was noted and commented on by the Rev. J. H. C. Bonte, in a 

 paper read before the Agassiz Institute in July, eighteen hundred and 

 seventy-six, on the northerly winds of the great central valley of 

 California. He said: "These winds are more virulent and desic- 

 cating in the extreme north and the extreme south ends of the val- 

 ley ; the atmosphere from the Golden Gate and the bays seem to 

 modify the wind ordinarily in the center of the valley." 



The tables of temperature confirm his inference. Tulare is four 

 degrees cooler for the year than the next station south and two 

 degrees cooler than the next station north, which may be referred to 

 the influence of the cold air from the high mountains at whose base 

 it is situated, and to the evaporation from Tulare Lake. 



Another effect of these deserts is to create a daily sea breeze from 

 the southwest return trade winds that prevail on the coast as surface 

 winds during the summer months. Each day, after the sun rises 

 over these great deserts, they become heated and increase the temper- 

 ature of the air over their surface; this air rises, and as the whole 

 current of cool air is from the ocean on the west, it rushes in to fill 

 the vacancy. A gentle southwest wind may be blowing on the coast 

 at night or in the morning ; by eleven or twelve o'clock the full force 

 of the sun's rays is felt in the Nevada Desert — the gentle breeze has 

 increased to a brisk wind, and continues until evening, after the 

 setting sun has withdrawn his rays and the desert has radiated its 

 heat into space. The gentle southwest w r ind resumes its sway until 

 the next day, when, from the same cause, the high wind is again 

 repeated. Dr. Gibbons, in an article on the climate of San Fran- 

 cisco in the Smithsonian report of eighteen hundred and fifty-four, 

 says: "Whatever may be the direction of the wind in the forenoon, 

 in the spring, summer, and autumn months it almost invaribly 

 works round towards the west in the afternoon. So constant is this 

 phenomenon that in the seven months from April to October, inclu- 

 sive, there were but three days in which it missed, and these three 

 days w r ere all rainy, with the wind from the south or south-south- 

 west." He adds : " I cannot discover that in any other spot on the 

 globe the wind blows from one octant one hundred and eighty-six 

 days, and from the opposite octant only six days in the year." 



The mean summer temperature (June, July, and August) at Wads- 



