THE CLIMATE OP MICHIGAN. 



689 



70" 



CHART IV. -Mean ten5)erature for the month 



of July. 



The most striking illustration of the lake effect is brought out by 

 Charts V and VI. These charts are drawn from data recorded during 

 the very cold month of January, 1912, and the very hot month of July, 

 1916, the temperatures used, being respectively, the lowest in January 

 and the highest in July. The moderating effect of all the lakes is shown 

 by Chart V. In the upper peninsula readings as low as -45° F. and 

 -46° F. were registered in the interior counties, while at Eagle Harbor 

 the north-most station, on the Keweenaw peninsula, the lowest reached 

 was -17° F. In the lower peninsula -39° F, was recorded at Gaylord, 

 Otsego county, but the lowest at Old Mission, on Grand Traverse Bay, 

 at the same latitude was -7° F. 



The July maximum temperature chart, (Chart VI), brings out the 

 cooling effect of the lalces, especially Lake Michigan during extremely 

 hot weather. Here the isotherms are crowded close together, parallel 

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