**** Info via Environment Canada
What is relative humidity?
When we think of high humidity, we probably think of a tropical jungle, but Canada has many locations typically humid: the Atlantic provinces, the Valley of the St-Lawrence, the Great Lakes, coastal towns in the Northern Territories and the coast of British Columbia. High humidity is beyond 70%. In winter, the humid cold intensifies our discomfort, penetrating our bones. In summer, high humidity clings to our bodies, causing stickiness, and for some, unruly hair!
When we typically imagine low humidity, our minds often drift toward the arid landscapes of the desert. Canada, specifically the Prairies region, showcases a surprising side with its own dry climate. Southern parts of Alberta and Saskatchewan are known to be more susceptible to droughts. With humidity levels dipping below 40%, the dryness provides some respite from intense heat, making it more tolerable. However, during winter, this lack of moisture can be a double-edged sword, as it irritates our lungs and has a knack for coaxing our noses into unexpected nosebleeds.
What is relative humidity?
Here’s an example of measuring humidity. In one cubic metre of air at 20 °C, 17 grams of water can evaporate and spread into that space. If this same volume of air holds only 8.5 grams of water, we say that it is half saturated and its relative humidity is 50%.
Relative humidity is the relationship between the amount of water vapour in the air and the maximum amount that could fill that space at a given pressure and temperature. A reading of 50% means that the air contains half the humidity it can hold before water droplets will form as clouds or dew.
What’s the dew point?
The dew point is the temperature to which a given volume of air must be cooled for it to become saturated. At night, as the temperature falls to the dew point, the relative humidity gradually increases until the water vapour in the air condenses as droplets on plants and other objects. When the dew point is reached in the freezing cold of winter, the water vapour condenses on objects as frost.
What is the relative humidity in your location right now? In the WeatherCAN app, you can find out by tapping on “NOW” and then on the down arrow to see the observations at the weather station nearest you.
