Last updated: July 2, 2025
In Sumna, Czech Republic, understanding the UV Index is crucial for safeguarding your skin against harmful radiation. With UV levels peaking at 8 during midday hours, awareness can play a vital role in preventing sunburn and promoting long-term skin health. The temperate climate of Sumna, characterized by mild summers, still brings its share of UV exposure risks, making it essential to stay informed about daily UV conditions. By knowing the UV Index, residents can enjoy the outdoors while protecting themselves from potential harm.
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 vary significantly, with the highest risk months occurring from May to August, where the UV Index reaches a peak of 9 in June and remains at 8 during July and August, indicating a very high exposure category and a critical burn time of just 15 minutes. In contrast, winter months see much lower UV levels, with January and November registering a UV Index of 2 and December dropping to 1, categorized as low exposure. Visitors and residents should exercise caution during the high-risk months by minimizing sun exposure, wearing protective clothing, and applying sunscreen regularly, particularly between late spring and early fall when UV radiation is at its strongest.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 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 |
| Sumna | 2 | 3 | 5 | 6 | 8 | 9 | 8 | 8 | 6 | 4 | 2 | 1 |