Last updated: June 2, 2025
Staying aware of the UV Index is crucial for residents and visitors in Kostajnica, Bosnia and Herzegovina. Understanding UV levels helps in taking proactive measures for sunburn prevention and maintaining skin health. With a climate characterized by warm summers, Kostajnica experiences significant UV exposure—particularly during midday hours where indices can reach up to 9. By staying informed about the UV Index, you can better protect yourself from the harmful effects of the sun and enjoy the beauty of this charming area safely.
The UV Index throughout the day presents a clear pattern of intensity, peaking at midday. Starting from a mild level of 1 at 07:00, the index rises steadily, reaching 2 by 08:00. The real surge occurs between 09:00 and 13:00, where it escalates from 4 to a striking 9—the highest point of the day. As the afternoon unfolds, the intensity slightly declines to 7 at 15:00, before tapering off to 5 at 16:00. The evening sees a further decrease, settling back to 2 by 18:00 and returning to 1 at 19:00. For those enjoying outdoor activities, it’s essential to take precautions, especially during the peak hours from 11:00 to 14:00 when the UV rays are most potent.
| 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 | 6 | high | 25 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 9 | very high | 15 min |
| 14:00 | 9 | 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, the UV Index fluctuates markedly, with high-risk months typically occurring from April to August. During this period, the UV Index regularly reaches very high levels, particularly in May, June, and July, where a burn time of just 15 minutes indicates an increased risk of skin damage. As the year transitions towards autumn and winter, the UV Index drops to moderate and then low, with safer exposure times of 30 to 45 minutes in effect during the colder months. Visitors and residents are advised to take precautions during the high-risk months by wearing sunscreen, protective clothing, and seeking shade, especially during midday hours when the sun's rays are strongest. Staying informed about the daily UV Index can help ensure safe and enjoyable outdoor activities year-round.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Kostajnica | 2 | 3 | 5 | 6 | 8 | 9 | 9 | 8 | 7 | 5 | 3 | 2 |
| Banja Luka UVI | 2 | 3 | 5 | 7 | 8 | 9 | 9 | 8 | 7 | 5 | 3 | 2 |
| Tuzla UVI | 2 | 4 | 6 | 7 | 8 | 9 | 9 | 8 | 7 | 5 | 3 | 2 |
| Zenica UVI | 2 | 4 | 6 | 7 | 8 | 10 | 10 | 8 | 7 | 5 | 3 | 2 |
| Mostar UVI | 2 | 4 | 6 | 7 | 9 | 10 | 10 | 9 | 7 | 5 | 3 | 2 |
| Sarajevo UVI | 3 | 4 | 7 | 8 | 9 | 10 | 10 | 9 | 7 | 5 | 3 | 2 |