Hitching is never entirely safe, and we don’t recommend it. Travellers who hitch should understand that they are taking a small but potentially serious risk.
In Finland hitching is possible, but expect long waits. It’s more common in remote areas where bus services are fewer, but still unusual. Your greatest friend will be your insect repellent. Mosquitoes can’t believe their luck that such a large juicy mammal would stand in one place for such a very long time.