42 



Temperature. 



Shade Temperatures. — The maximum shade temperatures are re- 

 corded for Tamale and Gambaga, where, towards the end of the dry 

 weather in February and March, the average is over ioo° F. The 

 lowest average record is from Tamale during the Harmattan month 

 of January, when the shade temperature falls just below 60° F. Both 

 greater and lesser individual temperatures are commonly recorded. 



The shade temperature within the Guinea Zone is very equable, 

 varying only some 20° in the coast towns, 23° in the Evergreen Forest, 

 and some 28° in the Deciduous Forest areas, between a maximum of 

 92° and a minimum of 64°. In the inland Sudanese Zone, however, 

 the variation is considerably more, from an average maximum of 

 over 100° to an average minimum of 64°, a difference of 36°. 



This comparatively even temperature under the modifying influences 

 of proximity to the sea and the presence of the forest and a greater 

 variation away from these influences and further inland naturally 

 follows. 



The stations are not sufficient, or sufficiently distributed, at present 

 to warrant setting these results down on an isothermic map. 



Maximum Solar Radiation. — The following data are obtained from 

 the records published under this heading in the meteorological statistics 

 of the country. The actual results must be accepted with reservation, 

 but the comparative results serve as a useful indication of the radiation 

 to be expected. 



The chief point noticed is that the results show two culminating 

 points for maximum solar radiation for both subdivisions of the Guinea 

 Zone and those of the Sudanese Zone. The chief culminating point is 

 in March and April, that is, during the tornado season towards the end 

 of the dry weather and before the heavy rains begin. The second 

 and lesser culmination is reached in October when the lesser rains are 

 faUing off and before the Harmattan begins. 



The records for the Coast Savannah, Evergreen Forest and De- 

 ciduous Forest lie between a minimum of 135° F. and a maximum of 

 150° F., a range of 15°. The Inland Savannah, whilst also extending 

 over a range of 15°, is in a considerably higher plane with a minimum 

 of 142° F., but a maximum of 157° F. The graphs illustrating this 

 result in connection with the monthly averages frequently intersect 

 in the cases of the Coast Savannah, Evergreen Forest and Deciduous 

 Forest, but that of the inland Savannah is entirely free and superior 

 to all three. 



The extreme range is between 161° F. at Gambaga, the most north- 

 erly station in the Inland Savannah, and at a height of- 1,300 ft. above 

 sea level, and 123° F. at Saltpond at sea level in the Coast Savannah. 



Minimum Terrestrial Temperatures. — The records are not considered 

 sufficiently rehable to reproduce and discuss in this connection. 



