Running late

We had a really wild, stormy night here last night, but today the clouds have gone and the sky is blue. I've happily wasted the lion's share of the day in the garden and have been amazed to swallows.
Five of them in the sun across the other side of the valley. The little group were feeding over river, presumably taking an opportunity to feed up. Swallows this late in the year is odd. Are they a late brood from here in Wales, or birds from further north feeding up on the way through?