Plenty of activity around my home bait hive around noon today. I was just on my way to the apiary to inspect and heard "that sound". Oh look! A swarm in flight, heading straight into my hive. I can see them settling in from my office window right now.
No idea if it's one of my colonies or not yet as I stopped to watch. It seems highly likely, but if so I'd have expected to hear them in their bivouac (assuming they bothered) as I have been working within about twenty metres of the apiary all morning. There was no clustering of bees on the front of any of my hives, either.
James