Cold season: winter, late autumn and early spring
Warm clothes including woolen sweaters, warm pants, hats, gloves, scarfs and warm boots are definetely needed during these seasons. Note: some monasteries and churches do not allow people in shorts and short skirts inside.

Warm season: summer, early autumn and late spring.
It is advisable to take light clothes such as jeans, T-shirts, sneakers, etc. Though it may be cool in the evening and at night, so long-sleeved clothes as well as a jacket are needed.

If you travel to the northwestern part of the country, in particular to the shores of the White Sea you are recommended to take some warm clothes with you, such as sweaters, light hats and wind and water proof jackets. It may be windy, cool and rainy there, that's why umbrellas can be useful as well.

Before travelling it is very useful to check on the essential things you may need during the trip. The recommendations on the basic things to take may be as follows: camera gear; daypack or waist-pack; spare eyeglasses/contact lens (if you need any); sunglasses (summer time); travel money bag; toiletries - toothbrush, toothpaste, and floss, hairbrush or comb, shaving items, deodorant, cotton ear swab; hairdryer (not available at all hotels); prescriction medicine and of course those things without which you cannot live your everyday life.