Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors of Juneau, as it plays a key role in maintaining skin health and preventing sunburn. Even in this cooler climate, the sun's rays can be deceptively potent during certain hours, with peak UV levels reaching as high as 9 around midday. With Juneau's unique Dfc climate, the risks associated with UV exposure may not be immediately apparent, making it important to stay informed. By monitoring and understanding the UV Index, you can enjoy the great outdoors while protecting your skin from potential harm.
The UV Index displays a dynamic pattern throughout the day, peaking at 12:00 PM with a striking value of 9, indicating a high risk of harm from unprotected sun exposure. Early in the day, the index starts low, with a maximum of 1 at 7:00 AM, gradually climbing to 3 by 8:00 AM and reaching 4 at 9:00 AM. As the sun climbs higher, the intensity escalates, hitting 6 at 10:00 AM and 7 at 11:00 AM. From 12:00 PM to 2:00 PM, the index remains at its peak of 9, suggesting that sunscreen and protective clothing are essential. Following the zenith, the index begins to decline, dropping to 7 at 3:00 PM, 5 at 4:00 PM, and further down to 2 by 6:00 PM. The day winds down with values of 1 at 7:00 PM, marking a significant decrease in UV exposure. Stay sun-safe and mindful of these daily fluctuations!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 3 | moderate | 30 min |
| 09:00 | 4 | moderate | 30 min |
| 10:00 | 6 | high | 25 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 9 | 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 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
The UV Index displays significant seasonal variation, with high-risk months occurring from May to August, when the UV Index reaches its peak at levels 8 to 9, indicating a very high exposure category and a quick burn time of just 15 minutes. In contrast, the winter months of January, February, November, and December exhibit a low UV Index of 1, allowing for safer sun exposure with no risk of quick burns. The transition period from March to April sees a moderate risk level with UV indices of 4 to 5, necessitating caution as burn times decrease to 30 minutes. Residents and visitors are advised to prioritize sun safety measures, particularly during the high-risk months by wearing protective clothing, applying sunscreen frequently, and seeking shade to minimize the risk of skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Juneau | 1 | 2 | 4 | 5 | 8 | 8 | 9 | 9 | 6 | 3 | 1 | 1 |
| 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 |