Friday, March 19, 2010

Peak UV Times

Our sunrise/sunset tables can be used to determine the time of peak UV radiation in your area.  Simply look up the time of Solar Noon on our tables - this happens to coincide with peak UV time.  Just remember to add one hour to our tables if Daylight Time is in effect.

Take precautions 2-1/2 hours either side of solar noon.  For example, solar noon occurs in Toronto tomorrow at 1:25 p.m. EDT, therefore, the danger period runs from about 11:00 a.m. to 4:00 p.m.

For a free sun table for the current month in your location visit our Sun Tables page at

Environment Canada states:
  • "The amount of UV you receive depends on both the strength of the sun's rays (measured by the UV Index) and the amount of time you spend in the sun. Reduce your time in the sun – seek shade, particularly between 11:00 a.m. and 4:00 p.m. from April to September.
  • Cover up, wear a broad-brimmed hat, a shirt with long sleeves and wrap-around sunglasses or ones with side shields
  • Use sunscreen – with a sun protection factor (SPF) of 15 or higher, with both UVA and UVB protection. Apply generously before going outside, and reapply often, especially after swimming or exercise
  • Listen for Environment Canada’s UV Index – it’s included in your local weather forecast whenever it is forecast to reach 3 (moderate) or more that day."
For more info and tips on UV protection from Environment Canada, visit  

Cheers, Ralph 


  1. I HAVE A QUESTION, is the uv more dangerous the summer?

  2. UV intensity increases as the sun is higher since there is less atmosphere to travel through at higher sun angles. Accordingly, UV peaks at solar noon and is stronger in summer than winter. UV can still have an effect in winter especially when reflected off large areas of fresh snow. (Source: Health Canada)

    Cheers, Ralph