518 



H. MOHN. METEOROLOGY. 



[nORW. POL. EXP, 



THE ANNUAL PERIOD. 

 The following Table gives the mean amount of cloud for each month 



Annual Mean 623 



— Minimum 3-59 December 28*'' 



— Maximum 8-84 July 27"' 



— Range 5-25 



From October to April, the amount of cloud is below the mean for the 

 year, from May to September it is above. The winter months are remark- 

 ably clear, the summer months very cloudy. PI. VIII. (1 cm. = 2 of cloud-scale). 



The average number of clear days and of overcast days are 



PI. VIII. 1 mm. 



1 day. 



