Yesterday afternoon looked like this in Wigton.
Mrs B made the following observations:
1. It felt warmer outside than inside the house.
2. Condensation had appeared on the outside of the water butts in mid-afternoon. Note: condensation, not rain.
I am guessing that a warm front passed over. The air behind the front is warmer. Water has a high specific heat capacity so a cold night and morning had left the water inside the water butt chilled. It takes a long time for water to warm up again. But the warm afternoon air was humid and laden with water vapour. When it hit the cold surface of the water butt, the water vapour condensed. This even though the plastic is an insulator. Remember than insulators are just bad conductors so given enough time thermal energy can move through them. The plastic did feel cold to the touch.
