Last updated: May 3, 2025
In Grayson Valley, understanding the UV Index is crucial for safeguarding your skin's health against the sun's harmful rays. With our Cfa climate, marked by warm and humid summers, UV exposure can reach significant levels, peaking at an intense 11 around midday. Recognizing these UV levels not only helps in preventing sunburn but also plays a vital role in reducing long-term skin damage. By staying informed and taking necessary precautions during peak UV hours, residents can enjoy the outdoors while keeping their skin safe and healthy.
Throughout the day, the UV Index experiences a dramatic increase, peaking at 11 between noon and 1 PM, indicating a very high level of solar radiation. Early risers will notice a gentle start, with a UV Index of just 1 at 7 AM, gradually climbing to 4 by 9 AM. As the sun reaches its zenith, values soar to 9 at 11 AM, signaling it's time to take precautions. After the peak, the UV Index begins to decline, dropping to 10 at 2 PM, then tapering off to 3 by 5 PM and resting back down to 1 by 6 PM. Staying protected in the midday sun is crucial for skin safety during these 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 | 7 | high | 25 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 7 | high | 25 min |
| 16:00 | 5 | moderate | 30 min |
| 17:00 | 3 | moderate | 30 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index varies significantly throughout the year, peaking during the summer months and indicating the best precautions for sun exposure. January and December see moderate UV levels (Index 4), with a burn time of 30 minutes. February marks the transition to high UV levels (Index 7) and a reduced burn time of 25 minutes. The high-risk period begins in March, escalating to very high levels (Index 8 and higher) in April and an extreme UV Index of 11 from May through August. Visitors and residents should take extra precautions during these months, limiting sun exposure to just 10 minutes and using protective clothing, sunscreen, and shade to prevent skin damage. Risk levels decrease in September and October, providing some relief, though caution should still be exercised given the high index readings. In summary, stay vigilant during the peak months of May to August, ensuring safe sun practices to guard against harmful UV radiation.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chicago UVI | 3 | 4 | 6 | 8 | 9 | 10 | 10 | 9 | 8 | 6 | 4 | 2 |
| Brooklyn UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| New York City UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| Grayson Valley | 4 | 7 | 8 | 10 | 11 | 11 | 11 | 11 | 9 | 7 | 6 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |