Answer:
It depends.
Explanation:
Hot water will evaporate all on its own. In fact, cold water will also evaporate. It depends on how much water is already in the gas above (i.e., the humidity). If the humidity is 100%, then liquid water is in equilibrium with the gas above it. Water molecules will evaporate at the same rate they condense. Even at cooler temperatures, there is still enough energy in water for one of the molecules to occasionally get bounced out of the container into the air.
I wonder if you may be asking about the boiling point of water. At 100 degrees C, water boils (212 degrees F). These numbers assume 1 atmosphere pressure and on the Earth's surface. As the elevation increases, the boiling point of water decreases. The slight reduction in gravitational pull allows more molecules to escape in the the air.
If you are asking what temperature does water have to be to form steam, that also depends on the temperature and humidity of the airspace.
