1. By: Arlene Waryszak, Brianna Danelon, and Christina Sisti

2. What is HUMIDITY? Humidity is the measure of the amount of water vapour in the atmosphere. The more water vapour there is in the atmosphere, the more humid it becomes.It is what causes those sticky and muggy days.

3. What Causes HUMIDITY? Humidity is caused by evaporation and condensation. Water evaporates into the atmosphere, which is caused by solar radiation being absorbed. In the atmosphere, water vapour is converted back into liquid form when air masses lose heat energy and cool. This is responsible for most clouds and also produces rain.

4. Time of Year HUMIDITY Occurs... Humidity mostly occurs during the warm months usually in the summer. It does not occur in the winter because the cold air cannot hold as much water vapour than warm air can.

5. Where in the World is HUMIDITY? ? Humidity is found nearly everywhere in the world. However, it occurs most often in areas along and around the equator because the Sun’s rays directly hit the equator. Also, humidity is found near large bodies of water because of the heat and moisture given off. Places such as the North and South Pole are least likely to have humidity. ? ?

6. Is There HUMIDITY in Ontario? Yes there is. Nearly everyone who lives in Ontario has experienced humidity. This is mainly due to the Great Lakes. The Great Lakes generate heat and moisture causing the humidity. DID YOU KNOW… Windsor is known to be the humidity capital of Canada.

7. HUMIDITY's Destruction Humidity does not cause many environmental problems, although when there is high humidity, it may cause wood to expand making doors and drawers hard to open. d Humidity causes many health problems, such as dehydration, heat exhaustion, and in the extreme, heat stroke and hypothermia. Humidity will also cause arthritis to worsen.

8. HUMIDITY's Destruction A lack of humidity can also cause problems. It can cause dryness in the membranes of the nose, throat and bronchial tubes, respiratory infections, repeated attacks of winter colds and airborne infections.

9. How Often HUMIDITY Occurs Humidity occurs mostly in the summer because the summer has the hottest weather, and warm air holds more moisture. Also, humidity mostly occurs near lakes and oceans because of the moisture coming from the water. (i.e. the Caribbean)

10. Factors of Weather that Interact to Produce HUMIDITY Water evaporates into the atmosphere. When the air is warm, the water vapour is easier to hold. In the atmosphere, water vapour is made back into water droplets when air masses lose heat energy and cool. Evaporation, condensation, and air temperature interact to produce humidity

11. Definitions Relative Humidity–the amount of water in the air relative to the saturation amount of air can hold at a given temperature multiplied by 100 Absolute Humidity–the percentage of water vapor actually present in the air Dew point–the temperature at which water vapour saturates from an air mass into liquid or solid usually forming rain, snow, frost, or dew.

12. Interesting Facts • There is no such thing as "heat lightning". So-called heat lightning is just lightning from a thunderstorm too far away to be heard • Adding water vapor (humidity) to the air lowers density, weight and pressure of the air • The temperature of the water molecules remains the same while the molecules change state • Humidity is the main reasons for school absentees • Humidity is the #1 reason for hospitalization of children • Hair length increases with humidity.

13. Thank you for listening to our presentation on Humidity The End