WEATHER IN CRANBERRY CULTURE 



47 



Table 4. — Average Departure of the Mean Daily Temperatures From 

 Normal During the Ten- Day Periods Before the More 

 Harmful Cranberry Frosts — Massachusetts. 



(Degrees Fahrenheit) 



Date of Frost 



New 



Bedford 



Taun- 

 ton 



Middle- 

 boro 



Ply- 

 mouth 



East 

 Wareham 



Hyannis Average 



Sept. 17. 1868 +1.60 



Sept. 8, 1871 -0.70 



June 1, 1875 +2.45 



May 31, 1876 0.00 



May 12. 1878 +0.50 



June 6, 1879 +4.40 



Mav 29, 1884 +2.30 



June 14, 1884 +1.35 



Oct. 2, 1886 -2.55 



Sept. 6, 1888 -2.90 



Sept. 30, 1888 -8.15 



June 10, 1892 +1.95 



May 14, 1894 +4.85 



May 13, 1895 +8.95 



May 28, 1900 -1.05 



May 25, 1903 +10.10 



May 31, 1903 +4.55 



Sept. 22, 1904 -2.80 



May 23, 1905 -1.80 



May 20, 1906 +5.75 



April 28, 1910 +7.90 



June 4. 1910 +0.95 



June 9, 1912 +3.20 



Sept. 15, 1913 -7.30 



May 29, 1915 -0.45 



Sept. 10, 1917 



June 20, 1918 



May 24, 1921 +5.35 



May 27, 1922 +6.90 



May 23, 1923 +6.45 



May 14, 1936 



Mean Temperature Before Frosts 



The average departures of the mean daily temperatures from the normal 

 means in 10-day periods, at places of observation in or near the cranberry dis- 

 tricts of Massachusetts, New Jersey, and Wisconsin, just before the widely 

 destructive cranberry frosts in those regions are given in tables 4, 5, and 6. They 

 show that temperatures precedent to the more serious spring frosts have usually 

 been above normal, only those before the June frost of 1918 in Massachusetts^* 

 having been substantially below.^* Temperatures before the fall frosts, on the 

 other hand, have tended to be below normal. ^5 These considerations enter here: 



1. High temperatures hasten drying of the ground by both evaporation and 

 plant transpiration and so tend to reduce the conductivity and specific heat of 

 the surface soil. Also much of the heat coming to the ground is consumed directly 

 in evaporation. 5^ These factors are more important in the latter and more 



^^This frost came in a well-established drouth. 



^^Widely harmful cranberry frosts closely preceded by a week or so with both supernormal 

 rainfall and subnormal mean temperature hardly ever occur anywhere (May 27, 1927, in New 

 Jersey) in the spring. 



^^No widely destructive cranberry frost closely preceded by a week or so with both rainfall and 

 mean temperature above normal has ever occurred anywhere in the fall, except that in mid-Sep- 

 tember 1895 in New Jersey. 



"^Geiger, op. cit., pp. 4-6. 



