312 



JAS. J. SIMPSON — ENTOMOLOGICAL 



was 110 rain were November and February. At the same time, the monthly 

 rainfall is also greater in the south than in the north. 



The maximum rainfall for one day for the years 1905-1908 was as follows : 

 In 1905, 4'04 inches at Ilorin on June 2nd ; in 1906, 7*27 inches at Zungeru ; in 

 1907, 4" 15 inches at Ilorin on September 9th; and in 1908, 5 inches at Ilorin 

 in Octolier. 



Consequently no definite periods can be given for the wet and dry seasons in 

 jSIorthern Nigeria, but in a general way it may be said that the duration of the 

 dry season decreases, whereas the amount of the monthly rainfall increases from 

 the north to the south. 



Table C. 

 Maximmn and Minimum Humidity, 





1906. 



1907. 



1908. 



1909. 



1910. 



Min. 



Max. 



Min. 



Max. 



Min. 



Max. 



Miu. 



Max. 



Min. 



Max. 



Geidam 











26 



81 



24 



81 



29 



83 



Bauchi 



22 



73 



— 







— 



— 



26 



82 



26 



77 



Kano 



— 



— 



28 



81 



— 



— 



27 



83 



28 



75 



Sokoto 



— 



— 



22 



86 



— 



— 



27 



76 



25 



72 



Nafada 



— 



— 



— 



— 



— 



— 



29 



81 



33 



84 



Katagum 



— 



— 



— 



— 



26 



86 



30 



76 



28 



70 



Zaria 



?>2 



80 



— 







32 



80 



31 



79 



33 



80 



Kontagora ... 



24 



So 



30 



90 



— 



— 



32 



80 



27 



84 



Maiduguri 



— 



— 



25 



84 



— 



— 



34 



86 



34 



79 



Birnin Kebbi 



— 



— 



— 



— 



— 



— 



35 



91 



33 



83 



Yola 



.32 



82 



33 



79 











30 



80 



24 



84 



Keffi 







— 



— 







— 







36 



80 



36 



85 



Zungeru 



.31 



85 



38 



82 



39 



84 



44 



89 



33 



86 



Ibi 



31 



81 



40 



84 



— 



— 



55 



79 



39 



80 



Baro 



— 



— . 



— 



— 



55 



83 



59 



77 



58 



84 



Lokoja 



57 



78 



61 



78 



73 



84 



04 



81 



59 



80 



Ilorin 



55 



81 



61 



81 



63 



88 



65 



81 



51 



85 



Ankpa 



— 



— 



— 



— 



58 



88 



67 



85 



64 



86 



Another factor which must be taken into account is the degree of humidity in 

 the various districts. Table C has been added to show the available records for 

 the years 1906-1910. It is unnecessary to analyse these in any detail, but the 

 following observations may bring out the salient features : — (1) The variations in 

 the maxima are very slight as compared with the minima ; for example, in 1909, 

 the highest and lowest maxima are 85 and 76, and the highest and lowest minima 

 are 67 and 24, while the corresponding numbers for 1910 are 86 and 70, and 64 

 and 24. (2) The contrast between Greidam and Ankpa, referred to above, is 

 again emphasised. At the former station, the difference between the maximum 

 and minimum for one year was 57 degrees in 1909, and 54 degrees in 1910, 

 whereas at the latter the corresponding difFerences were only 18 degrees and 

 22 decrees. 



