Last updated: June 2, 2025
Being aware of the UV Index is crucial for residents and visitors in Portsmouth, United Kingdom, where the charming maritime climate can mask the risks of sun exposure. Understanding UV levels is essential not only for preventing sunburn but also for maintaining long-term skin health. Despite Portsmouth's temperate climate (Cfb), the peak UV Index often reaches levels that can pose risks, especially during midday hours when it soars to 8. As you enjoy the beautiful coastal scenery, staying informed about the UV Index can help you protect yourself and make the most of your time outdoors.
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, the UV Index exhibits significant seasonal variations, with peak levels typically occurring during the summer months. January and February have low UV ratings (Index 2), allowing for relatively prolonged exposure without risk of burning (45 minutes). As spring approaches, March (Index 4) and April (Index 5) see a shift to moderate levels, reducing safe exposure times to 30 minutes. The high-risk months are May through August, where the UV Index reaches its highest points—7 to 8—requiring caution with burn times of just 15-25 minutes. September remains a high-risk month (Index 6) before it tapers back to moderate values in October (Index 4). By November and December, UV exposure risks reduce significantly. Residents and visitors are advised to stay vigilant during peak UV months, wearing protective clothing and sunscreen, especially between late spring and summer, to safeguard against 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 |
| 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 |
| Portsmouth | 2 | 2 | 4 | 5 | 7 | 8 | 8 | 7 | 6 | 4 | 2 | 1 |