Last updated: June 2, 2025
In Harpenden, United Kingdom, staying informed about the UV Index is essential for safeguarding your skin health and preventing sunburn. As residents enjoy the temperate climate characteristic of a Cfb zone, understanding UV levels can make all the difference during those sunny days, especially between 11 AM and 3 PM when the index peaks at 8. With such values, the risks of overexposure increase, making it crucial for everyone to adopt protective measures when stepping outside. Whether you're planning a leisurely afternoon in the park or heading out for daily activities, awareness of the UV Index helps preserve your skin and enjoy the vibrant summer days safely.
As the sun rises, the UV Index begins its steady climb, starting from a gentle 1 at 7:00 AM. By 10:00 AM, it reaches 5, signaling an increase in UV exposure. The peak occurs at 12:00 PM, hitting a robust 8, where caution is advised, especially for outdoor activities. The intensity remains high at 8 from 1:00 PM to 2:00 PM, encouraging sun protection measures. As the afternoon progresses, the index gradually declines to 6 at 3:00 PM, then further to 3 by 5:00 PM. Finally, as the day winds down, the UV Index settles at 1 by 7:00 PM, reflecting a much safer environment for evening activities. Enjoy the sun, but remember to protect your skin during those peak hours!
| 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 | 6 | 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 exposure varies significantly, with notable increases during the spring and summer months. From January to February, the UV Index remains low (1-2), allowing for safer outdoor activities with a burn time of 45 minutes. As we progress into March and April, the levels rise to a moderate range (4-5), reducing burn time to 30 minutes. The high-risk months of May through August see a dramatic increase, with UV Index values reaching 7-8 (high to very high), which significantly shortens burn time to 15-25 minutes. Finally, from September to October, the risk decreases as the UV Index drops to moderate levels (4-6), returning to safer exposure times. Visitors and residents are advised to take precautions during high-risk months by wearing sunscreen, protective clothing, and seeking shade, especially during midday hours, to minimize the risk of skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Liverpool UVI | 1 | 2 | 3 | 5 | 7 | 8 | 8 | 7 | 5 | 3 | 2 | 1 |
| Sheffield UVI | 1 | 2 | 4 | 5 | 7 | 8 | 8 | 7 | 5 | 4 | 2 | 1 |
| Birmingham UVI | 1 | 2 | 4 | 5 | 7 | 8 | 8 | 7 | 6 | 4 | 2 | 1 |
| Harpenden | 1 | 2 | 4 | 5 | 7 | 8 | 8 | 7 | 6 | 4 | 2 | 1 |
| London UVI | 1 | 2 | 4 | 5 | 7 | 8 | 8 | 7 | 6 | 4 | 2 | 1 |
| Bristol UVI | 1 | 2 | 4 | 5 | 7 | 8 | 8 | 7 | 6 | 4 | 2 | 1 |