Last updated: August 1, 2025
Understanding the UV Index is crucial for residents and visitors in Tretten, Norway, where outdoor activities are plentiful in a picturesque climate. With UV levels peaking around noon, awareness of these daily fluctuations is essential for preventing sunburn and promoting long-term skin health. In Tretten's cool, temperate Dfc climate, even moderate UV exposure can lead to potential risks, especially during the summer months. By staying informed about the UV Index, you can enjoy the beauty of Tretten while safeguarding your skin from harmful effects of the sun.
As the sun rises, the UV Index takes its first steps, starting at a gentle 1 at 07:00. By 08:00, it climbs to 2, and by mid-morning, it reaches a moderate 3. The intensity peaks at 12:00 with a significant 6, signaling that midday sun is at its strongest. As the clock ticks past 13:00, the UV Index hits its maximum at 7, urging outdoor enthusiasts to take precautions. Gradually, it begins to wane, dropping to 6 by 14:00, then easing further to 5 by 16:00. As evening approaches, the index falls to 3 at 17:00 and concludes the day gently at 1 by 19:00, allowing a breath of relief as the sun sets.
| 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 | 4 | moderate | 30 min |
| 12:00 | 5 | moderate | 30 min |
| 13:00 | 5 | moderate | 30 min |
| 14:00 | 5 | moderate | 30 min |
| 15:00 | 5 | moderate | 30 min |
| 16:00 | 4 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index exhibits significant seasonal changes, impacting the risk of UV exposure for visitors and residents. The low-risk months are from January to March, with UV Index values of 1 to 3 and burn times of up to 45 minutes. As spring progresses into April and May, the UV Index increases to moderate and then reaches high levels in May, June, and July (UV Index of 6 to 7) where burn times drop to just 25 minutes. August marks a decline to moderate levels before it further decreases in September and October, returning to low-risk conditions by late fall and winter. Therefore, it is crucial for visitors and residents to be particularly cautious and protective during the high-risk months of May, June, and July, using appropriate sun protection measures such as sunscreen, hats, and sunglasses to minimize skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Trondheim UVI | 1 | 1 | 2 | 4 | 5 | 6 | 6 | 5 | 3 | 2 | 1 | 1 |
| Bergen UVI | 1 | 1 | 3 | 4 | 5 | 7 | 6 | 5 | 4 | 2 | 1 | 1 |
| Oslo UVI | 1 | 2 | 3 | 4 | 5 | 7 | 7 | 5 | 4 | 2 | 1 | 1 |
| Tretten | 1 | 1 | 3 | 4 | 6 | 7 | 7 | 5 | 4 | 2 | 1 | 1 |
| Drammen UVI | 1 | 2 | 3 | 4 | 5 | 7 | 7 | 5 | 4 | 2 | 1 | 1 |
| Stavanger UVI | 1 | 1 | 3 | 4 | 6 | 7 | 6 | 5 | 4 | 2 | 1 | 1 |