The weather in Hungary is mildly seasonal. Winters are cold, but not too cold. It does snow, but not so much that it causes a big problem. If you have a good overcoat, hat, gloves, scarf and thermals you can stay outside almost all day. Although I can't imagine why you'd want to.
Summers are fairly humid, and it can get uncomfortable to be in the sun too long.
It wouldn't be so bad with shorts and t-shirt, but we don't have that option. Short-sleeve shirts are a real blessing on hot summer days. A couple pairs of machine washable slacks are nice, too. You probably won't be wanting to wear dry-clean only wool suit pants every day. Hungary's very flat, and in spring and fall rain can blow in without much notice and it blows out just as quickly.