Warmer temperatures cause the water molecules to have a higher amount of kinetic energy and will therefore produce a higher frequency and magnitude of collisions between water molecules. This leads to a faster rate of evaporation. Boiling water will evaporate at a faster rate because of the same reason. At a lower atmospheric pressure, less energy is needed by the water molecules to escape into the atmosphere. Therefore more molecules at the water surface will be able to reach the required energy level and evaporation will occur at a faster rate.