Would dew believe it?

Would dew believe it? Finding the temperature at which the air begins to form dew is a way of gauging the air’s humidity.

You will need:

tin can
thermometer
crushed ice
bowl
water

What to do:

Half fill the bowl with crushed ice.
Ensure the outside of the can is completely dry.
Fill the can with cold water.
Place the thermometer in the can.
Add one tablespoon of crushed ice and stir.
Continue adding the ice until a layer of dew is visible on the outside of the can.
Immediately read the temperature on the thermometer to find the dew point temperature.
If it is high then the humidity is high also – watch out for the downpour!

What’s going on?

All air contains water vapour. As air cools (when it comes in contact with the cold can), the water vapour begins to condense. This is why glasses holding cold drinks "sweat" in the summertime. The dew point is the temperature at which moisture in the air begins to form dew. The higher the dew point temperature, the higher the moisture content of the air.

Read this for more information on humidity and the weather and for the full lowdown on weather click this.