Made in Canada: The UV and AQHI indexes that protect our health
Before you head out this Canada Day, make sure to check the AQHI and UV ratings so you can celebrate in comfort and safety!
Canada is home to a diverse range of weather, so it shouldn't come as a surprise that it's also the birthplace of innovative weather tools and technology.
We use these tools daily to communicate the forecast, which keeps people safe and informed.
In honour of Canada Day, we're highlighting the Air Quality Health Index and the UV Index, invented right here at home.
The UV Index is now a household name
On May 27, 1997, Canada became the first country to issue a daily nationwide ultraviolet (UV) forecast, informing people about the strength of the sun and associated risks.
It was first developed in 1992 by three Environment and Climate Change Canada (ECCC) scientists: James B. Kerr, C. Thomas McElroy, and David I. Wardle.
The reading is called the UV Index.
Since its establishment, Canada has become a leader in providing UV information to the public. We forecast the UV rating based on the thickness of the ozone layer, the atmosphere, the angle of the sun above the horizon, and the amount of cloud cover in the sky.
More recently, our forecasters expanded their data to include elevation, due to the sun's rays being stronger in higher altitudes, especially when there is snow reflection.
The UV Index is now used in several countries, including the United States, Australia, and most of Europe.
The AQHI
In 2005 the Air Quality Health Index, or AQHI, was created, a collaborative effort that came about with the help of experts from ECCC, Health Canada, provincial government, and other experts. This reading informs Canadians about health risks in the air.
The Air Quality Index (AQI) is a tool used by many government agencies to communicate to the public how polluted the air is and how polluted it may become over 48 hours.
The newer AQHI takes into account the health effects and environmental concerns associated with varying concentrations of pollution, two factors the AQI does not. AQHI measures the impact of air quality on your health using a scale of 1-10, with 10 or more representing the highest risk.
To date, the highest AQHI rating in Canada was recorded on Historic AQHI reading in Canada in August 2017 when wildfires in Kamloops, B.C. pushed the AQHI rating to 49, with concentrations of fine particulate matter averaging around 684.5 micrograms per cubic metre at one point in the downtown area - more than double the daily average that's considered hazardous in China.
Before you head out this Canada Day, make sure to check the AQHI and UV ratings so you can celebrate in comfort and safety!
You can find the information for both by searching your local forecast.
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Header image: Made by Cheryl Santa Maria for The Weather Network with images and graphics from Canva Pro.