Last updated: July 2, 2025
In Waterloo, Canada, being aware of the UV Index is crucial for safeguarding your skin health and preventing sunburn. Understanding the UV levels helps residents take proactive measures against harmful UV radiation, especially during peak hours. With a Dfb climate, Waterloo experiences a mix of seasonal highs and lows; however, summer months can bring significant UV exposure, particularly between 11 AM and 3 PM, when the index peaks at levels 7 to 9. Stay informed and protect yourself while enjoying the beautiful outdoors!
As the sun rises, the UV Index begins its ascent, starting at a mild 1 at 07:00. By 08:00, it climbs to a 2, indicating a low risk of harm from unprotected sun exposure. However, from 09:00 onwards, the intensity builds, peaking at 9 between 13:00 and 14:00—a time when precautions are essential to protect skin from damage. The afternoon hours see a slight decrease, dropping to 8 at 15:00 and further declining to 4 by 17:00. As the sun sets, the UV Index falls back down to 1 by 19:00, marking a return to safer levels. Stay vigilant during those midday hours to enjoy the sunshine while keeping your skin healthy!
| 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 | 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, 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 |
| Waterloo | 2 | 4 | 5 | 8 | 9 | 10 | 9 | 9 | 7 | 5 | 3 | 2 |