Quote:
"If water evaporates at 100degrees C then how come steam comes from non boiling water?
"
It doesn't - water vapour does.
If you can see it, it has already condensed back into water.
Quote:
"How come its also more noticable if the hot liquid is in a cold enviroment "
What is "it"?
If "it" is noticable, it is no longer a gas - it is tiny water droplets that have condensed.
Consider this analogy.
Generally speaking, the hotter a liquid is, the more solvent it can dissolve.
Similarly, the hotter the air, the more water vapour it can hold.
If you cool down a saturated solution, the excess solute will crystalise out as visible crystals.
If you cool down a saturated gas, the excess water vapour will condense out as visible droplets.
Above a cup of hot tea, the air will become warmed and hold a relatively high level of invisible water vapour. This hot moist air is less dense than surrounding air and will rise. As it moves into cooler air above, the excess water vapour will condense out as visible droplets. This is a small-scale imitation of how clouds form.