Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Cornwall, Canada, where the climate can present significant sun exposure risks. With maximum UV levels peaking at 8 around midday, it's essential to stay informed about potential sunburn and long-term skin health issues. Being aware of the UV Index helps guide safe outdoor activities and ensures protection against harmful rays, especially during the sunnier months. Cornwall’s Dfb climate features warm summers and high UV exposure, making it imperative for locals to prioritize sun safety and enjoy the beautiful outdoors without compromising their health.
The UV Index throughout the day presents a clear and vigorous pattern of intensity. As the sun rises at 07:00, the index starts at a gentle 1, indicating minimal risk. By 08:00, it climbs to 2, still in the low range, but things escalate quickly; by 09:00, it reaches 3. The sun's power peaks astonishingly at 12:00, hitting a maximum of 8, which signifies a high risk for unprotected skin. This intense exposure persists until 14:00, before gradually tapering off through the afternoon. By 15:00, the index drops to 7, then diminishes further to 5 at 16:00, and continues to decline into the evening hours, settling back down to 1 by 19:00. Those planning outdoor activities during the midday hours should take care to protect themselves from the sun’s powerful rays!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 8 | very high | 15 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index shows significant seasonal changes, indicating varying levels of sun exposure risk. The highest risk months are from April to August, where the UV Index reaches 7 to 10, classified as high to very high, with burn times diminishing to just 15 minutes during this peak period. In contrast, the winter months of January and December exhibit much lower UV levels, categorized as low, allowing for 45 minutes before burning occurs. It is crucial for visitors and residents to be especially vigilant during the high-risk months. Sunscreen, protective clothing, and avoiding peak sun hours are strongly advised to minimize the risk of skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Edmonton UVI | 2 | 3 | 5 | 6 | 7 | 7 | 8 | 7 | 6 | 4 | 2 | 1 |
| Calgary UVI | 2 | 3 | 4 | 6 | 8 | 8 | 9 | 8 | 7 | 4 | 2 | 1 |
| Cornwall | 2 | 3 | 5 | 7 | 8 | 10 | 8 | 8 | 7 | 5 | 3 | 2 |
| Montreal UVI | 2 | 4 | 5 | 7 | 9 | 9 | 8 | 8 | 7 | 5 | 3 | 2 |
| Ottawa UVI | 2 | 4 | 5 | 8 | 9 | 9 | 8 | 8 | 7 | 5 | 3 | 2 |
| Toronto UVI | 2 | 4 | 5 | 8 | 9 | 9 | 9 | 9 | 7 | 5 | 3 | 2 |