53 



MAY 



Maximum air temperature, 65° F. 



Minimum air temperature, 36° F. 



Average air temperature, 44.8° F. 



Visibility was less than 4 miles 55 per cent of time. 



Visibilit}" was less than 2 miles 48 per cent of time. 



Figure 4. — May weather diagram. 



About twice as much bad visibility as the patrol's 8-year average 

 normal prevailed during May. On many of the foggy days the weather 

 was really fine the fog being simply a conduction phenomenon limited 

 to the layers of air chilled by contact with cold surface waters, with 

 the sun shining in a perfectly clear sky overhead. 



The month was featured by long periods of steady barometer about 

 30.00 inches in height. Moderate conditions prevailed and there was 

 a marked slowing down and several stagnations in the march of 

 Lows and Highs across the eastern half of North America and out 



