We did the Constellation Baltic cruise in late May of this year and it was wonderful. Other than two short downpours in St. Petersburg, the weather was spectacular. It was cool and windy in Tallin, but otherwise I'd call it "light jacket" weather. As a matter of fact, by the time we reached Rostock, it was quite warm. There are, of course, no guarantees. We heard the cruise following ours met with rather cool and wet weather all the way, so be prepared for anything.
The Baltic itinerary is incredible; every port is a gem with lots to see and do, but by no means is this a relaxing cruise. Because it is so port intensive, you might find yourself rather tired by the end - but it's worth it. Before our trip we read everything we could find on this and other cruise boards, and found lots of useful information from people who had already done this itinerary on both Celebrity and other cruiselines. Read the "Baltic ports," "Europe" and "Celebrity" boards and you'll be absolutely amazed by how much you will learn from cruisers who've already been where you're going.
We're not particularly fond of group tours so we generally stay away from shore excursions offered by the cruiselines. We had no problem at all touring on our own in all ports other than St. Petersburg. The ship docks very close to the center of town and Celebrity provides shuttle service to the town center in several of the ports. For the most part, the ports are walkable. We used Red October for our two days of touring in St. Petersburg and I highly recommend them. They were easy to work with (via the internet), very responsive and delivered everything they promised.
The Constellation is a beautiful ship - food, service, staff and crew are wonderful. In short, you're in for a very special time. We can't wait to do this cruise again. Enjoy!
