448 Eighth Annual Report of the 



Extremes of Monthly and Annual Temperature. 



The lacconipanjing table shows the warmest and coldest months 

 andi years which have occurred during a long period at four rep- 

 resentative localities of the State. 



At Fort Columbus, in New York hai'bor, the observations of 

 the entire series have presumablv been made under conditions 

 which would not cause discrepancies exceeding a degree in the 

 mean values, so thlat the differences shown may be attributed to 

 actual variations of weather. At Rochester the records) ^ere 

 kept by voluntary observers prior to 1871, and at the Weather 

 Bureau station thereafter; but the normal derived from the two 

 series do not differ by so much as 2 degrees for any months while 

 the variation for the year is but 0.3 degrees. There is some local 

 variation between the conditions at Potsdam and Grouvemeur, and 

 a small percentage of the differences shown in the table may be 

 attributed to this fact. The record at Burlington, Vt., has been 

 maintained without change of method or exposure of instruments 

 foT fifty-two years. The thermometers, although selected Iwith 

 care, were not standardized, and it seems probable that an in- 

 crease in the mean values for the summer months observable dur- 

 ing the latter part of the record may be due in part to instru- 

 mental error. 



In cases where the extreme values did not depart very widely 

 from the, averages, a considerable diversity was found even among 

 adjacent stations as to the seasons of greatest heat and cold, and 

 the best that could be done under these circumstances' was to 

 examine several records in each section of the State, selecting the 

 dates in ^which there was substantial agreement. The values 

 given for these dates are, however, those observed at the standard 

 stations of the table, excepting in a few cases where these were 

 found to be obviously in error, when the average was interpolated 

 from adjacent stations. 



It may be of interest to compare the extreme conditions in the 

 vicinity of New York city with the normal temperature of quite 

 different climates. 



The warmest January at Poirt Oolumbus=40 degrees. 



The average January at Norfolk, Va.^=40 degrees. 



