Sarah it's not clear where you come from, but I would suggest that you first of all get a guide book to Budapest and start from there. Again, not knowing what your home concept of 'temperature', all I can say is it will be COOL if not COLD, dark around 16H00. From my previous visits to Budapest I would say that safety should not be an issue if you take the same safeguards that you do at home. And as for comparing Sweden (a country) with Budapest (a capital city), that's not possible. Apples and oranges are both fruit, but are remarkably different.

Start with a good guide book and then ask. I am sure there will be more precise help on offer if you do some background reading first, and remember that good salesmen can sell icecream to the Inuit; it's up to you to want to go, rather than others to convince you! ;-)