( 46i ) 



Winter Temperatures . 



By Francis E. Nipher. 



The temperature of the December just past is above that of 

 any other in fifty-two years. The normal December tempera- 

 ture during that time is 33.5. The monthly means have varied 

 from 33.3 in 1S76 to 49.4 during the last year. 



For purposes of comparison, we may define a normal Decem- 

 ber, one which varies less than two degrees from the average of 

 the Decembers of 52 years. A mild December will fall within 

 a range of four degrees just above the normal range. Above the 

 mild Decembers, over a range of four degrees, will be the warm 

 Decembers, and above will He the very warm months. Simi- 

 larly below the normal, we have three four-degree belts, which 

 we may define as cool, cold, and very cold months. 



Including the month just past, the number of times the month 

 has fallen within these groups since 1S37, are given in the follow- 

 ing table. There have been two very warm Decembers, five 

 warm, thirteen mild, etc. Similar values for January and Feb- 

 ruary are given in the same table. 



Very warm 



Warm 



Mild 



Normal 



Cool 



Cold... 



Very cold .. 



December January. ' February. 



53 



52 



52 



It will be observed that the divergence of these Decembers 

 from the normal is very symmetrical. A probability curve 

 would represent them with precision. January, however, is a 

 month of extremes. There have been only 6 normal Januaries 



