I noticed over the weekend that 3 or 4 of my neighbours were adding to their wood piles at the side of the house, big piles of logs!

Is the bad weather coming soon? Some secret weather report out there. Or they just found it going cheap I wonder.

Simple matter of economics - supply and demand.
Wait until the cold weather is upon us and everyone will be chasing a diminishing supply ...... and pushing up prices.

Also, woodland is managed during the fair weather months, so trees will have been cleared and cut up, and will have dried a bit during the warm weather, although some timber may still be a bit green, so householders will still need to dry store this a bit longer.