THE SUNSHINE OF GUERNSEY FOR THE 

 YEAR 1915. 



BY MR. A. COLLENETTE, F.C.S. 



The year 1915 lias finished with a deficit of 97*6 hours as 

 compared with the average and a falling off of 71 hours as 

 compared with 1914. 



Two months, June and October, have totals smaller than 

 those recorded during the 21 previous years. 



The first month to show a large deficit was March, and 

 May followed, each of these months being below their averages. 

 The effect of this falling off" was accentuated by a deficit in 

 June of 71 hours, a deficit equal to the difference between 

 1915 and 1916. 



The total sunshine from January 1st to June 31st was 

 850 hours (nearly) instead of 970 hours. July, August and 

 September were sunny months with an excess over the average 

 of 58 hours, but this was only half of the duration needed to 

 redeem the year. 



There is a peculiarity about the month of June brought 

 out by the observations of the 22 years, which would not be 

 evident but for them. 



June works out to be less sunny than either May or J uly. 

 Naturally it would be expected that inasmuch as July is the 

 sunniest month of the year, the totals would grow from May 

 to July evenly ; they do not. May's average is 246 hours 

 and July's 264, therefore June should possess an average total 

 of 255 hours, whereas it is only 242 hours. It is therefore 13 

 hours less than its position in the curve demands. 



As the calendar months are of unequal duration, it is 

 necessary to make a correction for the purpose of comparison, 

 and when this is done some of the deficiency of June disap- 

 pears ; for instance, the mean sunshine value of a May day is 

 8 hours, and as the average for May is 246 hours corrected by 

 the subtraction of 8 hours, the total becomes 238 hours, 



