MARYLAND GEOLOGICAL SURVEY 



155 



TABLE VII. 



MO.NTHLY AND ANNOAL MEAN TEMPERATUllES AT ST. INIQOES, MD., 1871-1S79. 



Highest means.... 46.3 1 44.5 ' 53.9 66.2 I 66.0 76.9 



Lowestmeans 33.1 34.7 36.7 49.6 , 63.0 I 66.6 



Range l*-2 9.9 17.3 16.6 3.0 10.3 



79.6 i 73.5 ' 64.6 62.9 | 47.8 59.4 

 73.3 60.3 53.4 43.6 32.2 63.8 

 6.3 13.2 I 11.2 20.3 i 16.6 5.6 



The marked contrasts in the summer and winter mean temperatures 

 in St. Mary's County are characteristic of a continental climate, and 

 the differences become more striking if comparison be made between 

 exceptionally warm summer months and unusually cold winters. The 

 highest summer and the lowest winter means for each station are given 

 below : 



station. Highest Summer Mean. Lowest Winter Mean. 



Charlotte Hall 81.S° In August, 1000. 25.8° in February, 1S95. 



Cherryflelds 77.5° in July, 1898. 25.9° in Februai y. lsn5.' 



Leonardtown 78.2° in July, 1893. 25.6° in January, 1893. 



Ridge 84.1° in July, 1856. 26.6° in January, 1857. 



St. Inigoes 82.0° in July, 1876. 32.1° in January, 1872. 



St. Mary's 79.7° in August, 1864. 27.1° in January, 1867. 



^ From observations at 8 a. m. and 8 p. m. uncorrected. 



The highest monthly mean temperature in the county was 84.1° in 

 July, 1856, at Eidge, and the lowest was 25.6° in January, 1893, at 

 Leonardtown, giving a large range of 58.5°. 



THERMAL ANOMALIES. 



We may now inquire what relation does the corrected mean tempera- 

 ture for St. Mary's County bear to the normal temperature for its latitude, 

 in which the effect of the distribution of land and water peculiar to 

 the region in question may be considered to be equalized, if not elimi- 



