Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Portsmouth, United Kingdom, where the temperate maritime climate brings varying sun exposure throughout the year. Awareness of UV levels empowers you to prevent sunburn and protect your skin health, reducing the risk of long-term damage. Portsmouth experiences peak UV Index values reaching up to 8 during midday, making it essential to be mindful of outdoor activities, especially in summer. With this knowledge, you can enjoy the coastal beauty of Portsmouth while staying safe in the sun!
The UV Index throughout the day presents a clear and vigorous pattern of intensity. As the sun rises at 07:00, the index starts at a gentle 1, indicating minimal risk. By 08:00, it climbs to 2, still in the low range, but things escalate quickly; by 09:00, it reaches 3. The sun's power peaks astonishingly at 12:00, hitting a maximum of 8, which signifies a high risk for unprotected skin. This intense exposure persists until 14:00, before gradually tapering off through the afternoon. By 15:00, the index drops to 7, then diminishes further to 5 at 16:00, and continues to decline into the evening hours, settling back down to 1 by 19:00. Those planning outdoor activities during the midday hours should take care to protect themselves from the sun’s powerful rays!
| 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 | 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 |