Factors affecting the rate of evaporation

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Temperature
Wind


Exposed surface area
Humidity






"Water" Crossword | Evaporation and Boiling | Effect of Humidity & Temperature on Evaporation
Interactive Assessment Worksheets © by Alan & Hui Meng




Water molecules are always moving; at the water's surface, some molecules are bumped by molecules below them and gain enough speed to break free and escape into the air as gas [water vapour]. This escape of surface molecules is called evaporation ... it involves a change of state, from liquid to gas.

Evaporation takes place all the time and at any temperature.

The higher the temperature, the higher the rate of evaporation. When the temperature of water is increased (e.g., shining a powerful spotlight at it), the water molecules gain more energy, move faster and escape at a faster rate.