Where have all the conkers gone?

The leaves on the horse chestnut trees are already turning brown - they look very strange against the green of the other trees. There are a few conkers on the ground and a few still on the trees, looking like lime green alien growths amongst the brown leaves, but nothing compared to the amount that here ususally is in September. OK, so it's still a little early for conkers, but its way too early for all the brown leaves too. They should be yellowing a little, not the horrible brown dried up things that we have at the moment. Is it the sudden lack of rain we've had over the last two weeks? Seems unlikely considering the massive amount of rain we've had over the rest of the summer.