STUDIES IN LAKE AND STREAMSIDE VEGETATION 



J 39 



pair of evaporimeters was also set up and readings taken for a few 

 weeks. At points distant 10 miles (16 km.) or more from Redrock 

 Lake there have been "voluntary observers" who made records of tem- 

 peratures and precipitation for short periods but these records are so 



Fig. 4.— Mean March of Temperature by Hours for the Week Ending at 

 Midnight June 28, 1908. 



The upper line is Boulder, the lower, Redrock Lake. The temperature shown 

 for each hour is the mean for the seven records of that hour. It will be noted that the 

 minimum temperature at both stations is reached at 5:00 a. m. At Redrock Lake the 

 maximum is at 12:00 M. with a depression at 1:00 and 2:00 p. M. due to the thunder 

 showers which occurred nearly every day during the week. The flatness of the Boulder 

 curve at the corresponding hours is the result of temporary clouds which often appear in 

 the early afternoon even when there is no shower. 



incomplete and probably so unreliable that they cannot be used. 1 

 Something of the climate may be inferred from what is known of other 



• Some fragmentary observations on air and soil temperatures in the mountains of Boulder County are 

 given in an article by Robert T. Young in the Botanical Gazette, Vol. XLYI, pp. 321-52, 1907. 



