SUNSHINE IN GUERNSEY. 



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



We now have 16 years averages of sunshine. Compared 

 with the 67 years period for rainfall this is a very short time 

 and it is not to be expected that the figure quoted as the 

 average sunshine, 1917*2 hours, is really the sunshine of 

 Guernsey, for we have just passed through and for all we 

 know, may be still passing through a cold series of years. 

 The year just concluded has been one of average heat it is 

 true, but the summer had no period of sustained summer 

 heat and the average temperature has been kept up more 

 by the relatively high temperature of the winter months 

 than by the warmth and sunshine of the summer months. 



We would have fared very badly had it not been for the 

 excessive sunshine of one month, May. This month stands 

 out as an altogether unusual one. The average daily sunshine 

 we expect in May is 7*9 hoars, raised this year to 8 hours, and 

 when I say that the mean daily value this year was 10*9 hours, 

 say 1 1 hours, you will realise that there has been last May a 

 mean of 3 hours excess per day for the whole month. 



The following analysis of the duration per day will enable 



you to realise the excess. 



Days' without sunshine ... ... ... 0 



under 5 hours ... ... ... ... 2 



„ between 5 and 10 hours ... ... 9 



„ 10 „ 11 „ 1 



„ „ 11 ,, 12 j, ... ... 1 



» » 12 „ 13 „ 6 



,, „ 13 14 „ ... ... 9 



„ ,, 14 „ 15 „ ... ... 3 



„ under 10 hours ... ... ... 11 



„ over 10 hours ... ... ... ... 20 



The excess for the month of May was 89 hours, as it 

 appears in the table where the average for May stands at 

 250*4, hours but as this avesage has been raised by the month 

 itself from 244*4 hours it follows that the gain of this May 

 [1909.] I 



