26 PLANT LIKE OK ALABAMA. 



'riif r:iiiu»' lu'twfcii till' lowest and liij^licst iiiraii tciii])<'i-al iii'cs for a 

 jx'iiod of Iwt'Mlx -tlii"cf \cars ((tvci's ^>2 . with ;>."> in .lanuaiy and sT 

 in Julv for cxtrcnics. Tlic widest i-aiicre in the extremes ()f teiupeni- 

 ture observed once in that pei-iod covers 1(»4 between the absolute 

 miniimini of "J in January' an<l the absolute niaxiuiuui of loti in 

 .July. 



In the southei-n dixision of the Stiite. which is luaiidy embraced 

 within the isothermal lines of tis and (54 F., tiie lines of mean annual 

 temperatui-e follow with but slii>ht deviiition tln' parallels of latitude. 

 Between the isothermal line of <>4 and that of 6U"^ extends a central 

 belt closely foUowine- the terrace that divides the northern and south- 

 ern divisions of the State. The lines of nu'an annual temperature 

 of 00"^ and &2^ include its northei-n dixision. 



RAINFALL. 



The meteorological region including Alabama receives the supply 

 of moisture for its precipitation ])rincipally from the Gulf of Mexico. 

 In the distribution over time and space the rainfall is of great uni- 

 formity. According to the records of the State weather service,^ 

 consisting of observations made at the 48 different stations through 

 periods of from tw'o to over thirty years, the amuial rainfall for the 

 entire State is about 52 inches. Of this amount 14.52 inches falls 

 during the winter months, December, January, and February; 14.83 

 inches in the spring; 13.21 inches in the summer, and not quite 10 

 inches (9.55) in the autumn. The greatest annual rainfall does not 

 exceed (55 inches at any place and the least falls not below 41.75 inches. 

 The numl)er of rainy days in a year observed during a period of six 

 successive years fluctuates between 74 and 117, according to the records 

 kept at ^lontgomery: no periods of w^et weather (>xtend over five 

 days.- 



Snow falls occasionally in the northern i)art of the State; usuall}' 

 one considerable snow fall occurs during midwinter. In the lower 

 part it snow^s very rarely. 



Such a plentiful and evenly distributed, but not excessive, supply 

 of atmospheric moisture, in connection with a mijd and (equable tem- 

 perature, is productive of a highly luxuriant vegetation, which is most 

 strikingly exhibited in its arboreal growth. 



WINDS. 



In its correlation with temperature, precipitation, and cloudiness, 

 wind exercises a potent influence upon the climate. The prevailing 



' On February 13, 1899 (not included in the above period) , the temperature fell at 

 Tuscaloosa to 6° or 7° lielow zero F. and at Mobile to 3° below. 



2 P. H. Mell, Climatology of Alabama, op. cit., pp. 28,29,59. 



*E. A.Smith, Agrieultiiral Features of Alal)aiiia. Report of Geological Survey of 

 Alabama for 1880 and 1881. 



