Last updated: July 2, 2025
Understanding the UV Index is essential for residents of Greenstone, Canada, where the climate can elevate sun exposure risks throughout the year. With the potential for high UV levels, particularly around midday when the index peaks at 8 from 1 PM to 2 PM, being aware of these levels can significantly aid in preventing sunburn and protecting skin health. As the picturesque surroundings beckon outdoor activities, knowing when to seek shade or apply sunscreen is crucial in safeguarding yourself and enjoying the sun responsibly in this Dfc climate zone. Stay informed, stay healthy!
As the sun rises, the UV Index begins its gradual ascent, starting at a mild 1 by 07:00. By 09:00, it nudges up to 2, marking the beginning of greater awareness for sun protection. The intensity peaks at 12:00, with a robust 7, leading to 13:00 and 14:00, where it reaches an impressive 8—the prime time for outdoor activities. As the afternoon light begins to wane, the index dips to 6 by 16:00, and further declines to 4 at 17:00. The evening cools down with a UV Index of 2 by 19:00, reminding us that while sun exposure is crucial for a sunny day, vigilance is key as we enjoy the longer hours of daylight.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 2 | low | 45 min |
| 10:00 | 3 | moderate | 30 min |
| 11:00 | 5 | moderate | 30 min |
| 12:00 | 7 | high | 25 min |
| 13:00 | 8 | very high | 15 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 2 | low | 45 min |
Throughout the year, UV exposure varies significantly, with high-risk months typically occurring from April to August. April marks the beginning of elevated UV levels, peaking in May and June with a UV Index of 8 and 9, categorizing these months as having very high exposure and a burn time of just 15 minutes. As summer progresses into July and August, the UV levels remain consistently high, requiring extra precautions. By September, the UV Index decreases to 6, transitioning from high to moderate risks. Visitors and residents should take care during these high-risk months by applying sunscreen, wearing protective clothing, and seeking shade to prevent skin damage. As we approach the fall and winter months, notably October through December, the UV risk declines significantly, allowing for more relaxed outdoor activities.
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 |
| Greenstone | 2 | 3 | 4 | 7 | 8 | 9 | 8 | 8 | 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 |