Last updated: August 1, 2025
Understanding the UV Index is essential for residents of Eureka, California, where the combination of coastal and Mediterranean climates can lead to varied UV exposure throughout the day. Awareness of UV levels offers crucial insights for preventing sunburn and maintaining overall skin health, especially as midday levels can soar to a striking 11—indicating an increased risk of harm from unprotected sun exposure. With Eureka's mild climate and sunny summer days, being informed about UV intensity helps safeguard against skin damage, allowing you to enjoy the beautiful outdoors while keeping your skin safe and protected.
As the sun rises, the UV Index begins its modest ascent, starting at a gentle 1 around 7:00 AM and 8:00 AM. By 9:00 AM, it picks up to 3, hinting at a sunnier day ahead. The peak intensity occurs from 11:00 AM to 1:00 PM, where it skyrockets to a striking 10 at 12:00 PM, reaching an impressive 11 by 1:00 PM—perfect for those sun-seeking adventurers! However, after this zenith, the UV Index gradually declines, dropping to 9 by 3:00 PM and further easing to a 4 by 5:00 PM. By 6:00 PM, it falls to 2, and as the sun sets, it returns to a safe 1 by 7:00 PM. Remember to take precautions during those peak hours to protect your skin from harmful rays!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 2 | low | 45 min |
| 10:00 | 4 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 9 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index experiences significant fluctuations, indicating varying levels of sun exposure risk. The high-risk months for UV exposure are primarily from April to August, where indices peak at 11 in June and July, categorized as extreme with a burn time of only 10 minutes. It is crucial for both visitors and residents to take precautions during this period, such as wearing protective clothing and applying sunscreen frequently. As spring transitions into summer, the UV index rises sharply, reaching very high levels in May and August, and dropping to high in March and October. The months of January, November, and December see lower risks with a moderate index of 3 or 5, allowing for more extended safe sun exposure times of 30 minutes. Visitors and residents should monitor UV levels closely and adjust outdoor activities accordingly to safeguard their skin health.
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 |
| Eureka | 3 | 6 | 7 | 9 | 10 | 11 | 11 | 10 | 9 | 7 | 5 | 3 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |