Yes, water can evaporate at all temperatures. That's why water disappears from a glass you leave out overnight (No stupid!... It's NOT because Santa drank it. JK) Under 100 C, water only evaporates on the surfaces exposed to open air. Over 100, water evaporates all throughout the container.

Short answer: Yes, it does. If it did not, then there would be no clouds or precipitation, because there would be no significant amounts of water going into the air to produce these phenomena. Also, if water did not evaporate at temperatures of less than its boiling point, then wet laundry hung out on a clothes line would never get dry. As a matter of fact just about nothing would dry out because, excluding active lava flow, there is no place on Earth's surface where the temperature exceeds 100 degrees C. Long answer: Air of any given temperature can contain some amount of water vapor. Just how much water vapor it contains depends on the air temperature. (The higher the temperature, the more water vapor air can hold.) If the air does not contain all of the water vapor that it can potentially hold, then water will evaporate from whatever water sources are available until the air does contain as much as possible. At this point, the air is said to be saturated. Another way to look at this is in terms of a concept known as partial pressure. Each component of a mixture of gasses contributes some portion of the total pressure of this mixture. The portion of the pressure that is contributed by each component is called the partial pressure. The proportion of the pressure that water vapor can contribute to the total pressure of the air varies with temperature. (This, again reflects the fact that the total amount of water vapor that the air can hold is temperature dependent.) If the partial pressure of water in the air is less than the total possible for water vapor, then water will escape from the surfaces of various water sources in the area. As water is evaporating, some of it is also condensing. However, as long as the partial pressure is below the total possible in the air, the rate at which the water evaporates will exceed the rate at which it condenses. However, as more water goes into the air, its partial pressure will increase. As its partial pressure increases, the rate of evaporation will decrease and the rate of condensation will increase. These changes in rates will continue until saturation occurs. At the point of saturation, the partial pressure of the water vapor equals the total possible for that given temperature. So, the rate of evaporation will equal the rate of condensation. In other words, water will be condensing out of the air as fast as it is evaporating. So, evaporation will occur even at temperatures that are well below 100 degrees C. The significance of the boiling temperature for a substance (any substance) is that that it is the maximum temperature at which that substance will be stable as a liquid. You will not be able to raise the temperature of the substance above its boiling point without first turning it into a gas. A simple experiment that you can try to illustrate this is to take a cooking thermometer and stick into a pot of cold water. Then place the pot on a stove and turn the heat on. As energy is added to the water, you will be able to watch the temperature of the water rise. That is, the temperature of the water will rise until it starts to boil. Once the water starts to boil, the temperature will remain constant. It does not matter how high the heat is or how vigorously the water is boiling. Its temperature will stay at 100 degrees C as long as there is any liquid present and you continue to add heat to the water. It should also be noted that the boiling point is dependent on atmospheric pressure. The lower the pressure, the lower the boiling point will be. For example, water boils at much lower temperatures at the top of high mountains than it will at sea level because of the much lower pressures present at the top of the mountains. As an extreme example liquid water is not even stable on the present day surface of Mars because its atmospheric pressure is so low. If you are to place an ice cube out on the surface of Mars on a day during which the temperature got above the freezing point, then the water in the ice would turn directly into gas rather than pass through the liquid phase (a process called sublimation). So, just to reiterate, water will evaporate at temperatures that are significantly lower than then 100 degrees C. The significance of that temperature is that it is the maximum temperature at which water can be stable as a liquid at the average atmospheric pressure at sea level.

Seeing that 100 C is equivalent to 212 F, I would certainly hope so! We all would be in trouble if it did not!

because The boiling point of a liquid is the temperature at which the vapor pressure of the liquid equals the environmental pressure surrounding the liquid.[1][2][3][4] A liquid in a vacuum environment has a lower boiling point than when the liquid is at atmospheric pressure. And a liquid in a high pressure environment has a higher boiling point than when the liquid is at atmospheric pressure. In other words, all liquids have an infinite number of boiling points. The normal boiling point (also called the atmospheric boiling point or the atmospheric pressure boiling point) of a liquid is the special case at which the vapor pressure of the liquid equals the ambient atmospheric pressure.[5][6] At that temperature, the vapor pressure of the liquid becomes sufficient to overcome atmospheric pressure and lift the liquid to form bubbles inside the bulk of the liquid. The heat of vaporization is the amount of heat required to convert or vaporize a saturated liquid (i.e., a liquid at its boiling point) into a vapor. Liquids may change to a vapor at temperatures below their boiling points through the process of evaporation. Evaporation is a surface phenomenon in which molecules located near the vapor/liquid surface escape into the vapor phase. On the other hand, boiling is a process in which molecules anywhere in the liquid escape, resulting in the formation of vapor bubbles within the liquid. Saturation temperature and pressure

Yes. Evaporation takes place at all temperatures when water is exposed to air. 100 degree C is the boiling point when all of the water wants to turn into vapor, thats all.