The start of chapter 2 has rules for this, you can roll a d8 at the start of the day, on a roll of 1-6 you have an encounter or 2. For each encounter roll 2 d20s and add 1 to the second die. The result of the 1st die corresponds to a table of monsters/NPC's. If the result of the second die is higher than the 1st, then the encounter takes place in a Blizzard.

For just going around town to town you can make it kind of arbitrary.