Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of London, Canada, as it directly impacts skin health and crucial sunburn prevention efforts. With a Dfb climate, London experiences seasonal fluctuations in UV exposure, but during peak summer hours, UV levels can soar, reaching as high as 9 around midday. Being aware of these levels is essential not only for enjoying outdoor activities safely but also for protecting your skin from potential long-term damage. Whether you’re out for a midday stroll or soaking in the sun at the park, knowing the UV Index empowers you to take proactive measures against harmful rays and keep your skin healthy.
As the sun rises, the UV Index begins its ascent, starting at a gentle 1 at 07:00. By 08:00, it climbs to 2, indicating a mild increase in UV exposure. The real peak arrives at 12:00, where the index reaches a striking 9, underscoring the importance of sun protection during these hours. This high level remains steady until 14:00, followed by a gradual descent as the afternoon wanes: 8 at 15:00, 6 at 16:00, and continuing down to 2 at 18:00. As evening approaches, the UV Index drops to a soft 1 by 19:00, signaling a gentle close to the sun-soaked day. Remember to take precautions during the midday hours to safeguard your skin!
| 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 | 9 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV exposure fluctuates significantly. January sees a low UV Index of 2, while by February and March, it rises to 4 and 5, indicating moderate exposure and a burn time of 30 minutes. As spring progresses into April, the UV Index sharply increases to 8, categorized as very high, marking the beginning of high-risk months, which continue through May, June, July, and August with UV Index values reaching a peak of 10. Visitors and residents should take particular caution during these summer months, as burn time drops to just 15 minutes under peak conditions. September maintains a high risk with an 8 index, while the UV Index drops back to moderate levels in October (5) and November (4) before returning to low levels in December (2). To minimize the risk of UV exposure, it is essential for individuals to wear sunscreen, protective clothing, and seek shade, especially from late spring through early fall.
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 |
| 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 |
| London | 2 | 4 | 5 | 8 | 9 | 10 | 10 | 9 | 8 | 5 | 4 | 2 |