Last updated: June 2, 2025
Understanding the UV Index is crucial for residents and visitors in Castletown, United Kingdom, where the climate can often lead to increased sun exposure. Keeping track of UV levels is essential not just for avoiding painful sunburns, but also for protecting long-term skin health. During peak hours, particularly from 12 PM to 2 PM, UV Index values can reach as high as 7, indicating a moderate to high risk of harm from unprotected sun exposure. With Castletown’s temperate oceanic climate, awareness of these fluctuations is vital for everyone to enjoy the sunny days safely.
The UV Index throughout the day presents a notable rise and fall pattern, peaking at 12:00 PM with a strong index of 7. The morning starts with a gentle 1 at 7:00 AM, gradually increasing to 3 by 9:00 AM, making it a good time for a leisurely stroll before the sun reaches its zenith. The intensity escalates further, hitting 6 by 11:00 AM and maintaining a steady 7 from 12:00 PM to 2:00 PM, suggesting the need for sun protection during these hours for outdoor activities. As the afternoon wanes, the index begins to decline, dropping to 4 by 5:00 PM and gradually returning to a 1 by 7:00 PM, making the late evening more forgiving for those sensitive to UV exposure.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 6 | high | 25 min |
| 12:00 | 7 | high | 25 min |
| 13:00 | 7 | high | 25 min |
| 14:00 | 7 | high | 25 min |
| 15:00 | 6 | high | 25 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
As the seasons change, the UV Index fluctuates significantly, impacting how individuals should approach sun exposure. From January to February, the UV Index remains low (1), allowing for safe outdoor activities with a burn time of 45 minutes. However, starting in March, the UV Index rises to 3, marking the beginning of moderate exposure, where burn time decreases to 30 minutes. April and May see a steady increase, reaching a peak of 5 in May. The high-risk months are June through August, when the UV Index hits 7 and 6, respectively, reducing safe exposure to just 25 minutes. As the summer subsides into September and October, the UV Index falls back to moderate levels of 4 and 3. Visitors and residents should remain vigilant during high-risk months, seeking shade and wearing sunscreen to protect against harmful UV rays, while enjoying longer outdoor activities during the lower UV readings.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Castletown | 1 | 1 | 3 | 4 | 5 | 7 | 7 | 6 | 4 | 3 | 1 | 1 |
| 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 |
| 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 |