They may vary. It depends on the microorganism. If we are talking about bacteria as a microorganism - it can survive practically in every condition and environment. Still, researchers define 4 key factors: time, moisture, nutrients, and temperature. Time is needed for microorganisms to reproduce, moisture carries foods to the cells and carries waste away from the cell, nutrients are needed for the bacterial growth, and temperature should be appropriate for microorganisms to grow.
Here is something you can read about it: