Hi, the safest course is summer and spring, these seasons are very warm and convenient for traveling, especially if you are going on hikes or spending the night in tents, for example, I recently visited Russia, https://hellorussia.co.uk/russian-visa-invitation-letter/ helped me with my visa, and I was amazed with such beautiful nature, especially in summer, when all the flowers smell and open, animals freely walk through the forest, this is a magical sight, I advise everyone.