Last updated: June 2, 2025
In Fullerton, United States, staying aware of the UV Index is crucial for protecting your skin from harmful ultraviolet radiation. With the potential to reach levels as high as 11 during peak hours, understanding UV levels helps prevent sunburn and promotes long-term skin health. Fullerton’s Dfa climate brings sunny days that often lead to increased UV exposure, making it essential to know when to seek shade or slather on the sunscreen. Prioritizing UV Index awareness is your first step towards enjoying the great outdoors safely!
As the sun climbs higher, the UV Index takes a dramatic leap throughout the day. Starting at a gentle 1 at 07:00, it gradually rises to 3 by 09:00. The real intensity kicks in later, peaking at an impressive 11 around 13:00, a critical time when sun protection is essential. From there, a gradual decline begins, with readings of 10 at 14:00, 9 at 15:00, and tapering off to 3 by 18:00. Finally, the day winds down, returning to 1 by 19:00. It’s a vivid reminder of how important it is to safeguard against UV exposure during the sun’s most potent hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 9 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 5 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV levels display significant variation, peaking during the summer months. The high-risk months for UV exposure are April through September, with UV Index values reaching their peak at 11 in June, indicating an extreme risk of harm from unprotected sun exposure. Visitors and residents are advised to take precautions during these months, including seeking shade, wearing protective clothing, and applying sunscreen regularly. During lower UV months, specifically January, February, November, and December, while risks are moderate, it's still wise to remain vigilant as UV rays can still cause harm. Being informed about UV Index levels can help ensure a safe and enjoyable outdoor experience year-round.
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 |
| Fullerton | 3 | 5 | 6 | 9 | 10 | 11 | 10 | 10 | 8 | 6 | 4 | 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 |