High pressure
I've often wondered. Why does high pressure in winter lead to cold temperatures but in the summer lead to blisteringly hot barbecue weather?
A QNH of 1040 is over us which, during summer, would have me inside and the aircon on full. In the winter it means we shiver in 0 degrees.
Is it because it limits cloud cover? In the longer sunlight days of summer we get more heat, but in the short days of winter we get more clear night skies to loose any heat we got during the day?