Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Pasadena, United States, where sunny days abound and outdoor activities are a part of life. Awareness of UV levels helps prevent sunburn and promotes long-term skin health, making it essential for everyone, especially during peak hours. With Pasadena's Cfa climate, the UV exposure can be significant, particularly between 10 AM and 2 PM when the Index soars to highs of 9 to 10. Protect yourself and enjoy the sun safely by staying informed about UV levels and their impact on your skin.
At sunrise, the UV Index starts gently at 1 around 07:00, whispering the promise of a bright day. As the clock ticks, it climbs steadily, reaching 2 by 08:00 and 3 by 09:00. The real intensity kicks in at 10:00, spiking to 6, and by 11:00, it jumps to 8. The peak occurs at 13:00, hitting a robust 10, a clear reminder to seek shade or don protection. As afternoon drifts toward evening, the index gracefully descends: it remains strong at 9 at 14:00, then eases to 7 at 15:00, 5 at 16:00, and finally back to 3, 2, and a calm 1 by 19:00. Enjoy the sun responsibly!
| 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 | 6 | high | 25 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 9 | 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 demonstrates significant seasonal changes, highlighting the need for awareness regarding sun exposure. From January to February, UV levels are moderate (index 3-5), with a burn time of 30 minutes. As spring arrives in March, the index rises to 7, indicating high exposure risk with a reduced burn time of 25 minutes. The peak risk occurs from April through August, where the index reaches its highest levels (9-10) and burn times drop to just 15 minutes, categorizing these months as very high risk. In September and October, the UV index remains significant but decreases to high levels (7-8) with a burn time of 25 minutes. November and December return to moderate levels (index 3-5) with a burn time of 30 minutes. For visitors and residents alike, it is crucial to take protective measures, especially during the high-risk months from April to August, by using sunscreen, wearing protective clothing, and seeking shade during peak sunlight hours.
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 |
| Pasadena | 3 | 5 | 7 | 9 | 10 | 10 | 10 | 9 | 8 | 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 |