Last updated: June 2, 2025
In Janov nad Nisou, understanding the UV Index is crucial for protecting your health and enjoying the outdoors safely. As a region prone to varying cloud cover and UV exposure, staying informed about UV levels can help prevent sunburn and long-term skin damage. With maximum UV Index values peaking at 8 during midday hours, it's essential for residents and visitors alike to be aware of these risks, especially considering the area's Cfb climate, which can lead to deceptively high UV radiation even in seemingly mild weather. Prioritize your skin's health by checking the UV Index before heading out and taking necessary precautions!
Starting the day with a gentle UV Index of 1 at 7:00 AM, the sun gradually intensifies, reaching 2 by 8:00 AM. By 9:00 AM, the index climbs to 4, marking the beginning of a more active sun exposure period. The peak arrives at 12:00 PM, where the UV Index hits a robust 8, indicating that it's time to seek shade and lather on the sunscreen. Throughout the afternoon, the levels maintain a high of 8 until 2:00 PM, before gently tapering off to 7 by 3:00 PM and gradually declining to 5 by 4:00 PM, and further down to 3 by 5:00 PM. As the day winds down, the index falls to 2 at 6:00 PM and finally settles back to 1 by 7:00 PM, signaling a safe return to outdoor activities as the sun sets. Stay sun-smart and enjoy your day!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 4 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 8 | very high | 15 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV levels experience significant fluctuations, with high-risk months identified as April through August, during which the UV Index can reach as high as 8 and fall within the very high exposure category. Specifically, June and July are the peak months for UV exposure, requiring extra caution as the burn time shortens to just 15 minutes. In contrast, January, November, and December present the lowest UV indices, categorized as low exposure, allowing for safer outdoor activities with extended burn times of 45 minutes. To ensure safety, visitors and residents should remain vigilant in high-risk months, applying sunscreen, wearing protective clothing, and seeking shade during peak hours, while enjoying the more forgiving UV levels during the winter months.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Janov nad Nisou | 2 | 3 | 4 | 6 | 7 | 8 | 8 | 7 | 6 | 4 | 2 | 1 |
| Prague UVI | 2 | 3 | 4 | 5 | 7 | 8 | 8 | 7 | 6 | 4 | 2 | 1 |
| Ostrava UVI | 2 | 2 | 4 | 6 | 7 | 8 | 8 | 7 | 6 | 4 | 2 | 1 |
| Olomouc UVI | 2 | 3 | 4 | 6 | 7 | 8 | 8 | 7 | 6 | 4 | 2 | 2 |
| Pilsen UVI | 2 | 3 | 5 | 6 | 8 | 8 | 8 | 7 | 6 | 4 | 2 | 1 |
| Brno UVI | 2 | 3 | 5 | 6 | 8 | 8 | 8 | 7 | 6 | 4 | 2 | 2 |