You should bring normal clothes and shoes that you are used to wearing since the weather during the late spring, summer and early autumn is not different to that of mainland European countries. In addition, you need to be prepared for the winter. A good pair of waterproof shoes, a warm winter coat, woolen jumpers, thick warm socks, a scarf, pair of gloves and a woolen hat that also covers your ears will be needed. All of these items can also be bought in Finland of course. Hypermarkets offer good value and sell a wide range of such items during the season.
Finnish buildings, including schools are well heated and you should bear this in mind when dressing for school in winter. When considering shoes, you should also ensure that the base of the shoe has a good and strong grip. Streets of Helsinki are frequently cleared of snow and therefore it is not essential to have boots. When cleared of snow, the streets easily become covered with a layer of ice - a shoe with a smooth base will not support you on the ice.