Ontario

Very High UV Index Advisory in Effect for Cornwall This Week

By

boringnews
June 22, 2026 4:34 pm

Cornwall, Ontario, is under a very high UV index advisory for Monday and Tuesday, with readings expected to hit 8 on the UV index scale. Residents should take care when spending time outdoors, as unprotected skin can burn quickly even under cloudy skies.

Environment Canada forecasts mainly cloudy conditions Monday with a 30 percent chance of late afternoon showers, a high of 24°C, and a humidex of 29. Tuesday will see fog patches clear by morning, then a mix of sun and cloud, a high of 25°C, and a humidex of 28. The UV index will stay at 8 both days, and Wednesday is expected to be sunny with a high of 25°C.

When the UV index reaches 8 or higher, Health Canada advises limiting sun exposure, especially between 11 a.m. and 3 p.m. People should wear UV-blocking sunglasses, seek shade, and reapply sunscreen every two hours, or after swimming or sweating heavily. Even on cloudy days, UV rays can still cause burns.

Skin cancer is the most common cancer in Canada, making up about one third of all new cases, according to Health Canada. In Ontario, Cancer Care Ontario reports skin cancer rates have been climbing since the early 1990s, with annual increases of 2.3 percent for people aged 50 to 74 and 4.6 percent for those 75 and older.

Southern Ontario, including Cornwall, sees Canada’s highest UV index values because the sun’s rays are stronger at lower latitudes. With warm temperatures and sunny breaks ahead, this advisory serves as a reminder to practice sun safety over the coming days.

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