Volos harbour is suitable in most weather conditions. The prevailing winds in the harbour are from the south
Warning: the sea floor is covered with lines and chains, so beware of dropping an anchor.
The southern breakwater is suitable for alongside berthing.
The quay: the laid lines previously along the sea wall are all gone, leaving only rusty mooring rings on the quay. With a strong northlies the boat will be pressed against the quay. Fender heavily as there are rusty mooring rings along the wall. There are no services (water or power) on the sea wall quay.
The main quay is taken up entirely with local and charter boats. There are signs posted on the quay wall stating that the berths are for Permanent moorings only. While it may be possible to slip into one of these berths, there is no guarantee you can stay. However, as there is water available it may be possible to slip into a berth briefly to fill up with water (card for water is available at the Parking booth in front of the Port Authority building). The sea floor here is littered with old laid lines and chains also there is a fixed chain 50 m parallel to the main quay.
The Port Authority have 4 berths near the ferry terminal and they will charge to moor here. You may find you are directed to one of these berths. Anchor stern-to. Holding is good, although some parts of the harbour have rather soft mud.
The "yacht harbour" in the north is full of fishing and charter boats with no room for visitors. If you do find a space here, it is still close to the town and restaurants and there is no swell at all. Water and electricity are available.
There is a dock near the entrance to the 'marina' where it may be possible to berth for a few days. Generally, nobody appears to collect any fees.