How worried should I be?

I had our boat unwinterized a couple of weeks ago and took it out. Everything was fine and the weather was in the 70's. I put the boat back in storage and have not seen it since. The weather turned over the last couple of weeks and dropped down as low as 23 degrees at night. The high everyday has been at least 50. There were probably at least three straight nights where the temps dropped below 32, but always warmed up during the day. The boat is in a ghetto in-door storage. It is basically a metal warehouse with dirt flooring, but it is enclosed. I am headed up this weekend, but a little concerned about what I might find. Should I be worried? I am from California and never had to worry about it freezing before this.