Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Nanaimo, Canada, where the mild climate of the Cfb zone can still present significant sun exposure risks. As UV levels peak, especially around midday with readings reaching as high as 9, awareness of these fluctuations ensures you can protect your skin against sunburn and long-term damage. Embracing the beautiful outdoor lifestyle that Nanaimo offers means being mindful of UV levels; even when the day starts cool, the sun's intensity can increase rapidly, making it essential to stay informed and take proactive measures for your skin health all year round.
The UV Index throughout the day showcases a dynamic pattern of intensity. Starting at a mild 1 at 07:00, it gradually escalates as the sun climbs higher. By 10:00, it reaches 5, signaling a noteworthy rise. The peak occurs at 13:00, with a striking 9, indicating a high potential for harm without protection. Following this zenith, the index starts to wane, dropping to 6 by 16:00 and further diminishing to 1 by 19:00. This illustrates a critical window from 10:00 to 14:00 when caution is essential for outdoor enthusiasts looking to enjoy the sun safely.
| 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 | 6 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 9 | 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 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index exhibits notable seasonal changes, peaking during the summer months of May through August when it reaches levels categorized as very high. May sees a UV Index of 8, progressing to 9 in both June and July, before slightly declining to 8 in August. These months are particularly high-risk, with significantly reduced burn times of just 15 minutes for unprotected skin. As summer transitions to fall, the UV Index decreases, dropping to 6 in September and moderating to 4 in October, where the burn time increases back to 30 minutes. Residents and visitors are advised to take extra precautions during the high-risk months—wearing sunscreen, protective clothing, and sunglasses to reduce the risk of sun damage, especially during midday hours when the UV radiation is strongest. In contrast, the winter months from November to February present lower UV levels, with January and December categorized as low, allowing for safer outdoor activities without extensive sun protection.
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 |
| Nanaimo | 2 | 3 | 4 | 6 | 8 | 9 | 9 | 8 | 6 | 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 |