How to find your UV Index

How to find your UV Index

Environment and Climate Change Canada publishes a daily UV Index forecast bulletin for major towns and cities across Canada throughout the year. If the maximum UV Index value for the day is expected to reach 3 or greater then it is also included in Environment Canada's daily weather forecast. The UV Index is also included in most radio, TV, newspaper and online weather forecasts.

The UV forecasts are issued twice a day, at 5:00 am for the day, and at 4:00 pm for tomorrow, local time. The Index is updated hourly, if the cloud cover changes.

Finding the UV Index on Canada’s weather web site

Start by finding the weather forecast page for your location.  On this page, the UV Index is included in the text below the seven day forecast. 

A sample forecast page on Environment Canada’s weather.gc.ca website showing where the UV forecast

Summer 2016 UV outlook

Environment and Climate Change Canada scientists predict that UV values across Canada will be about 2 to 3 % higher this year during the summer months, and possibly even higher for some days in the spring, as compared to pre-1980 levels, due to the reduced thickness of the ozone layer.   

Summer UV values across North America

Typical summer values for the UV Index across North America show major changes from north to south.  In general, the farther south you go, the higher the UV Index. This is why you burn so quickly on a southern vacation.  

This table summarizes the typical early summer midday UV values for locations across North America - click to expand
LocationUV Index
Tropics10 - 14 (very high to extreme)
Grand Canyon area, AZ11 (extreme)
Washington, DC9 (very high)
Toronto8 (very high)
Ottawa8 (very high)
Montreal8 (very high)
Halifax8 (very high)
Calgary8 (very high)
Whistler, BC8 (very high)
St. John's7 (high)
Vancouver7 (high)
Victoria7 (high)
Edmonton7 (high)
Winnipeg7 (high)
Yellowknife5 (moderate)
Iqaluit5 (moderate)
North Pole2 (low)

Holiday travel and UV

Heading south for a holiday?  Be careful – in the Caribbean, Mexico, Hawaii and other tropical destinations you are further south and the UV is stronger.  On vacation you'll also likely wear fewer clothes and visit the beach, where UV reflects off the sand and the water.

If your vacation includes a winter climate, skiing and other outdoor winter fun can also increase your exposure to UV. Reflection off fresh snow nearly doubles UV, and if you are skiing in the mountains, you will receive more UV due to the elevation.

The UV Index is used in many countries around the world.  Check the World Health Organization for a list of countries with the UV Index.

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