CLIMATIC CONDITIONS OF THE UNITED STATES. 



217 



Table 6. — Summations of normal daily mean remainder indices of temperature efficiency for 



plant growth, for the period of the average frostless season. (Plate 38.) 

 [The daily indices are derived by subtracting 0, 32, 39, or 50 from the values of the normal daily 



mean temperature on the Fahrenheit scale.] 



