874 TWENTY-FIRST REI'ORT. 



}\ iiid: Rccoifls of wiiul direction and velocity are not kept at present. 

 Such records can in jienerai lie interpolated from Ihe records of the Weather 

 Bnrean stations at Cliebo.vfian. Charlevoix and St. Ignace, Mich, about 17 to 

 20 miles northeast, southwest and north respectively. The records from 

 J>ouglas Lake approach most nearly those of Cheboygan. 



^Vat^■l• Level: Records of the water level of Douglas Lake are kept by 

 the Engineering Camp on Douglas Lake, but have not been worked up for 

 this report. 



SiniitiKirif and Conclusion.^: As the purpose of this paper is merely to 

 make the meteorological data more available, no attempt will be made to 

 summarize the weather of the Douglas Lake I'egion further than to call atten- 

 tion to certain outstanding features of the summers. 



The weather conditions during the summer sessions are as a rule com- 

 fortable and conducive to active work. The average weekly temi)erature 

 varies from 67.6° during the first week to a maximum of 71.0° during the 

 fourth week, following which it drops gradually, reaching an average of 66.7° 

 during the last week of the session. Periods of very hot weather are unusual. 

 In only two out of seven years of records has a temperature of 100° or more 

 been reached three times in 1916 and twice in 1917. The night temperatures 

 are always satisfactory, in seven years a minimum of 70° or above having 

 occurred but sixteen times, eight of which were in 1916 — a memorably hot 

 summer throuout the middle west. But twice has the thermometer remained 

 above 80° during the night and that on consecutive nights at the culmination 

 of the severe hot wave late in July, 1917, during which 104°, the maximum 

 recorded temperature, also occurred. 



With the exception of the sixth week of the summer session, the rainfall 

 is moderate and rather scattering, averaging about .40 inches per W(>(>k 

 (.26 to .49). In the .sixth week, however, the second week following the maxi- 

 mum average temperature, there have been heavy rain storms during live 

 out of seven summers, making the average rainfall of that week 1.72, more 

 than four times as great as the average for any other week. In 1913, the 

 heaviest precijwtation occurred during the fifth week. 



The growing season is short, as frosts in June and September are of 

 normal occurrence. Once, in the .-oven years of record, frost occurred in 

 August. 



That the meteorological cuiiditions arc highly favorable and stimulaling 

 for tbf licld work nf which this station makes a specialty can easily be .seen 

 from these records. 



