Last updated: June 2, 2025
Awareness of the UV Index is crucial for residents and visitors of Mammoth Lakes, United States, where the stunning alpine landscapes come with a heightened risk of sun exposure. Understanding UV levels is essential for preventing sunburn and maintaining long-term skin health, particularly in this region known for its high elevation and clear skies. With UV indexes peaking at a striking 13 around noon, it's vital to stay informed about daily UV conditions to enjoy the outdoors safely and minimize skin damage. Given Mammoth Lakes' Csb climate, where chilly winters contrast with sunny summers, knowing when to seek shade or slap on sunscreen can make all the difference for your skin!
At dawn, the UV Index starts at a modest 1 at 07:00, gradually rising as the sun ascends. By 08:00, it reaches 3, and by 09:00, it hits 5, signaling that sunscreen may soon be needed. The intensity peaks at 12:00, reaching an impressive 13, while lingering at that level for an hour until 13:00. As the afternoon unfolds, the UV Index begins to decline, tapering to 10 by 15:00 and further dropping to 4 by 17:00. As the sun sets, the values fall back to 2 at 18:00 and a gentle 1 by 19:00. It's a day where sun safety is paramount during the midday hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 5 | moderate | 30 min |
| 10:00 | 8 | very high | 15 min |
| 11:00 | 11 | extreme | 10 min |
| 12:00 | 13 | 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 |