Does condensation and evaporation occur at the same time? What temperature condensation occur at?
Yes, they can occur at the same time.
Evaporation is the process whereby molecules of the liquid which possess enough kinetic energy escape from the liquid.
Condensation is the process whereby the molecules of the vapor which possess too little kinetic energy, and returns to the liquid. Considering distreibution of molecular velocities, at any given temperature range when the substance exists in liquid state there will be some molecules with too high kinetic energy and some with too low kinetic energy. Theoretically, condensation of vapours can occur at any temperature below its boiling point at the given atmospheric condition. In actual practice, several physical factors viz. pressure and volume of the surrounding atmospheric environment etc. could affect the event of condensation.