Last updated: July 2, 2025
In Mammoth Lakes, understanding the UV Index is crucial for safeguarding your skin against harmful solar radiation. With peak UV levels soaring to 13 around midday, awareness of these measurements is essential for preventing sunburn and promoting long-term skin health. The region's unique Csb climate means that even on cooler days, the sun’s rays can be intense, increasing the risk of skin damage. Stay informed and enjoy the beautiful outdoor adventures that Mammoth Lakes has to offer while keeping your skin safe!
As the sun rises, the UV Index starts its matin ascent, peaking at a powerful 13 by 1 PM. Beginning at a gentle 1 at 7 AM, the index climbs steadily, reaching 2 by 8 AM and surging to 5 by 9 AM. The real impact unfolds around 10 AM, where it hits 8, leading to a formidable 10 at 11 AM. By noon, the UV intensity escalates to 12, and shortly after, it reaches its zenith at 1 PM with a maximum of 13. As the afternoon unfolds, the levels begin to decline but still remain impactful, dropping to 12 at 2 PM and then tapering off to 10 by 3 PM. Evening settles in with a comforting decrease, as the index cools to 7 by 4 PM, gradually sinking to 1 by 7 PM, underlining the importance of sun safety during peak 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 | 8 | very high | 15 min |
| 11:00 | 10 | very high | 15 min |
| 12:00 | 12 | extreme | 10 min |
| 13:00 | 13 | extreme | 10 min |
| 14:00 | 12 | extreme | 10 min |
| 15:00 | 10 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV Index levels fluctuate significantly, impacting sun safety for visitors and residents. From January to March, the UV Index rises from 5 to a peak of 10, marking March as a high-risk month with a very high exposure category and a burn time of just 15 minutes. April to August sees extreme levels at 13, with April and June to July being particularly critical for sun exposure, necessitating protective measures for anyone outdoors. In September and October, the UV Index decreases to 10 and 8, respectively, remaining in the very high category with a burn time of 15 minutes. As the year progresses into November and December, levels drop significantly to 6 and 4, indicating lower risks with moderate exposure. Visitors and residents are advised to adopt sun protection strategies during the high-risk months, especially from April to August, including wearing sunscreen, protective clothing, and seeking shade during peak UV times.
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 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |
| Mammoth Lakes | 5 | 7 | 10 | 13 | 13 | 13 | 13 | 12 | 10 | 8 | 6 | 4 |