Last updated: June 2, 2025
Understanding the UV Index is crucial for residents of Holtville, United States, where the BWh climate brings abundant sunshine and heightened exposure risks. As UV levels can soar to dangerous heights—peaking at 12 in midday hours—awareness becomes essential for preventing sunburn and safeguarding skin health. By tracking the UV Index, you can make informed decisions about outdoor activities, ensuring you protect yourself and your loved ones from harmful rays during those peak hours. Stay informed and enjoy the California sun safely!
Starting the day with a low UV Index of 1 at 7:00 AM, the sun gradually climbs higher in the sky, causing the UV Index to rise sharply. By 10:00 AM, it reaches a moderate 7, but the real peak hits at 1:00 PM with a whopping 12 — a cautionary signal for everyone to seek shade and apply sunscreen. Fortunately, the intensity begins to wane later in the afternoon, dropping to 8 at 3:00 PM and continuing down to 1 by 7:00 PM. Remember, the sun might be at its brightest around midday, so stay protected during those high-risk hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 5 | moderate | 30 min |
| 10:00 | 7 | high | 25 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 12 | extreme | 10 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 8 | very high | 15 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 |
Throughout the year, the UV Index experiences significant fluctuations, with the highest levels occurring from March to August. March and April both exhibit a very high UV Index of 9 and 10, respectively, leading to a burn time of only 15 minutes. The peak months, May and June, are classified as extreme with a UV Index of 11 and 12, necessitating caution as the burn time reduces to just 10 minutes. July and August continue this trend, remaining in the extreme category, before a gradual decline in September to 10 (very high) and further down to high with an Index of 7 in October. The year wraps up with moderate levels in November and December, where the burn time increases to 30 minutes. Given these variations, residents and visitors should take extra precautions from March through October, particularly during May and June, by wearing protective clothing, applying high-SPF sunscreen, and seeking shade to minimize their risk of sunburn and long-term skin damage.
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 |
| Holtville | 4 | 6 | 9 | 10 | 11 | 12 | 12 | 11 | 10 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |