Four years ago, I wrote a short article on this topic, and I do not think I could do anything better now that I am four years older.

http://www.dostihovy-svet.cz/en/node/2762

What to wear for your trip to the Czech Republic for the second weekend in October depends on the weather. The weather in east Bohemia in early October is difficult to predict. September is often warm and pleasant. November is usually colder than in western Europe. The changeover can often be abrupt, and is not always accurately predicted by the weather forecast. It is not very helpful, but my advice is that you should be prepared for warm, sunny weather or cold, wet weather, or something in between, and you should not trust the weather forecast too much.