i:XPERIMENT STATION BULLETINS. 



431 



REPORT OF THE UPPER PENINSULA SUB-STATION. 



LEO M. GEisMAR, Superintendent ; c. d. smith, Director. 



[Special Bulletin No. 28.] 



WEATHER CONDITIONS. 



At the close of this, the fourth year of weather observations at this station, 

 it may perhaps be opportune to explain why three out of the four seasons have 

 been termed as "wet," even though the total amount of precipitation is much less 

 in the Upper Peninsula than in latitudes further south, as will be seen from the 

 following records of average yearly precipitation at stations extending from 

 Lake Superior to the Gulf of Mexico and at altitudes as nearly alike as possible. 



Average annual precipitation at stations 1,000 to 1,150 feet elevation, the 

 records being taken from Monthly Weather Review of the U. S. Weather Bureau 

 and covering a period of ten years or over. 



Stations. 



Lathrop (Upper Peninsula).. 

 Grayling (Lower Peninsula). . 

 Reed City (Lower Peninsula) 



Farml.ind 



Rockville 



Angola 



Spiceland 



Oregon 



Princeton 



Hudson 



Canton 



North Lewisburg 



Mansfield 



Mount Sterling 



Lexington 



Waynesboro 



Andersonville 



Knoxville 



Point Peter 



Atlanta 



Valleyhead 



State. 



ifichigan., 

 Indiana . 



Missouri . 

 Ohio ...'. 



14 



Kentucky 



11 



Tennessee 



M 



Georgia... 

 .'Alabama.. 



Eleva- 

 tion. 



1,142 

 1,134 

 1,016 

 1,101 

 1,100 



1,052 

 1,02.5 

 1.113 

 1,026 

 1,153 



1,070 



1,095 



1,1.54 



930 



995 



1,050 

 1,167 

 1,004 

 1,000 

 1,050 

 1,058 



Precip- 

 itation. 



32.32 

 33.20 

 33.70 

 36.81 

 37.45 



38.40 

 39.80 

 36.12 

 37.22 

 37.63 



39.35 

 40.14 

 43.59 

 46.76 

 44.04 



47.63 

 49.97 

 50.04 

 50.51 

 52.01 

 66.93 



These figures graphically show that precipitation increases in volume as one 

 proceeds southward, and a more extensive list would show that this increase 

 holds good for either higher or lower altitudes in all regions where moisture con- 

 ditions are not disturbed by natural obstacles such as high mountain ranges. 



Humboldt has given the following figures as the proportional quantity of rain 

 in different latitudes: 



0° 96 in. 



19° 80 in. 



45° 29 in. 



69° 17 in. 



The central part of the Upper Peninsula is in latitude 46.30 and the annual 

 rainfall, according to Humboldt's table should be 28.25 inches, providing the 

 great lakes were not exerting influences to raise the total rainfall above the aver- 



