We spent some time in Holland in December and part of January one year. I think you are from Reno. I would expect very similar weather. It will be cold but probably you will not have snow. I would expect temperatures to be around 40 degrees average and the days will be mostly overcast with some rain. It does differ from year to year. If it is a really cold year, it could be around freezing. The canals do not freeze every year.

What you do have to prepare for is cold with a bit of wind. Both Holland and Belgium are on the North Sea and there can be some very cold winds from the north. I highly recommend bringing a scarf, hat, gloves and a coat that is at least thigh length. The other item to keep in mind is Belgium is pretty far north and you will have very short days. In Holland, the sun wouldn't come up until almost 9am and it would set around 4pm.

The Thalys high speed train will allow you to do day trips to Paris and Amsterdam. You might also think about Cologne although that is about 2 1/2 hours train. Cologne might make a nice overnight weekend trip. But there are a several places to visit in the Low Countries. I would highly recommend Brugge, Antwerp and The Hague. I haven't been to Ghent but that might also be a good day trip. In Amsterdam, the zoo is open in the winter. The NEMO museum is also fun for kids but your child might be too young. In the Hague, Madurodam which is a miniature version of Holland is fun.

Happy Travels, Marta in freezing Washington State