8 STATE HORTICULTURAL SOCIETY. 



Nothing enters so into our daily lives as the weather conditions, and 

 while these are in a measure inconstant, yet at the same time they leave 

 indelible marks whereby we may trace their passage through the state and 

 also the effect they have on different portions of the state. 



The subject of the amount of rainfall in Michigan, and its distribution, 

 and the temperature lines of the state, is one which is of no little impor- 

 tance to those engaged in producing fruit or cereals. 



The "peach belt " of Michigan has been long an established fact, yet 

 the reasons or cause for it have never been satisfactorily explained. 

 Although the cause has been hinted at, yet the collection of the tempera- 

 ture and rainfall data of the state shows conclusively why this fruit can be 

 successfully produced on the west side of the state, and also why it can 

 not be made a success in other portions, soil of course being equal in all 

 cases. 



The temperature lines of the west side of the state are several degrees 

 higher than in the central portion or the east portion. For instance, it is as 

 warm in the Grand Traverse region as it is in the extreme southern tier of 

 counties in the east half of the state. 



During the winter season the warm air from the lake is carried over 

 the state, its warmth is taken out as soon as it strikes the cold land, and 

 is not conveyed far into the interior. The lake is probably never frozen 

 over entirely, and therefore the water must be above thirty-two degrees 

 and will probably be found to be about thirty-four degrees, and the winds 

 blowing over this large surface of water absorb the heat from the water 

 and carry it to the land, where it is transferred to the colder ground, keep- 

 ing the temperature of the "peach belt" higher than it is in the interior. 

 Again, in the spring of the year, the case is reversed, as the land warms 

 up rapidly under the influence of the warm rays of the sun, and while in 

 the interior the trees are putting forth their leaves and buds, which are 

 liable to be nipped by the frosts, those in the " peach belt " are still 

 retarded by the cool winds from off the lake and the buds do not come out 

 until after the danger from killing frosts has passed. Thus the lake acts 

 in both cases as a care taker of the fruit trees on the west side of the 

 state. 



During the fall of the year the prevailing southwest winds, carrying 

 the warmth from the lake, allow the trees to gradually prepare for the 

 winter and keep them from the sudden changes of temperature which 

 injure the trees of the interior, and in the spring the reverse applies as has 

 been stated. These are considered to be the principal causes for the rich 

 production of fruit on the west shore of the state. 



These causes have been partially understood, and Prof. Winchell 

 rightly surmised this effect in his study of the climate of the state; but 

 having so little data to work with, the full significance of this was not 

 brought out. 



It has been one of the first duties of the weather service to construct 

 temperature and rainfall charts which show graphically these facts, and 

 they are so constructed that any one can understand. 



Three of these charts, showing the normal temperature lines in the 

 state, are here shown, first the September chart, which shows the begin- 

 ning of the downward curve of the temperature ; second, the January 

 chart, which displays the winter dip of the temperature, and third, the 

 May chart, which displays the reverse curves and explains the cause for 

 the retarded growth in this region, while other portions of the state are 



