Last updated: July 2, 2025
Understanding the UV Index is essential for residents of Sarnia, Canada, as it provides crucial insights into daily sun exposure and the potential risks associated with high UV levels. Being aware of UV intensity helps in preventing sunburn and maintaining long-term skin health, especially during the sunniest peak hours when the index can reach a maximum of 9 at noon and early afternoon. Given Sarnia's Dfb climate, where seasons can vary significantly, knowing when to protect your skin is vital. Awareness of these UV risks not only promotes safer outdoor activities but also fosters a healthier lifestyle in the vibrant community of Sarnia.
As the sun rises, the UV Index starts off low at 1 between 07:00 and 08:00, making it a safe time for outdoor activities. However, as the day progresses, the UV levels climb sharply, hitting 3 by 09:00 and reaching a significant peak of 9 from 13:00 to 14:00. During these hours, it's crucial to take precautions, such as wearing sunscreen and protective clothing, as the intense UV radiation poses a considerable risk. The index gradually declines after this peak, dropping to 6 by 16:00 and further down to 1 by 19:00, signaling a return to safer conditions as the day winds down. Stay informed and protect yourself when the sun is at its strongest!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | 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 | 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 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index experiences noticeable fluctuations, impacting the risk of skin damage due to sun exposure. High-risk months are primarily from April to August, where the UV Index reaches very high levels of 8 to 10, necessitating caution with a significantly reduced burn time of just 15 minutes. In contrast, the UV levels are much lower from January to March and again from November to December, characterized by low to moderate exposure with burn times extending up to 45 minutes. Residents and visitors should be particularly mindful during the peak summer months, ensuring adequate sun protection such as sunscreen, hats, and clothing, and seeking shade during the day to minimize the risk of skin damage. Remember, smarter sun habits can help you enjoy the outdoors safely!
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 |
| Sarnia | 2 | 4 | 5 | 8 | 9 | 10 | 9 | 9 | 7 | 5 | 3 | 2 |