Last updated: July 2, 2025
In Mountlake Terrace, understanding the UV Index is essential for maintaining skin health and preventing sunburn, especially during peak hours when the index reaches levels of 8 to 9 around noon. With a Csb climate characterized by mild summers, residents may underestimate their sun exposure risks. However, even on overcast days, UV rays can penetrate clouds, making awareness of local UV levels crucial to protect your skin. Regularly checking the UV Index can help you plan outdoor activities safely, ensuring you enjoy the beautiful Pacific Northwest while minimizing potential harm from the sun.
As the sun rises, the UV Index begins its journey, starting low at 1 at 07:00 AM and gradually climbing. By 09:00 AM, it hits 3, but the real intensity kicks in by 12:00 PM, peaking at an impressive 8. The UV levels reach their zenith at 1:00 PM and 2:00 PM, where they maintain a high of 9, urging sun-seekers to take precautions. As the afternoon fades, the index gradually declines, dropping to 5 by 4:00 PM and further to 4 at 5:00 PM. As evening approaches, the index settles back down to a gentle 1 by 7:00 PM. It’s a vivid reminder of the sun’s strength—safety and sun protection are key during those peak hours!
| 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 | 5 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 8 | 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 |
As the seasons change, so do UV levels, significantly impacting sun exposure and skin safety for visitors and residents. January to March sees a gradual increase in UV Index, peaking with a moderate level in March at 5, where the burn time decreases to 30 minutes. The high-risk months, characterized by extremely high levels of UV radiation, are May through August, with indices soaring to 9 and enforcing a burn time of just 15 minutes. Following this, September presents a moderate risk with an index of 7, and a burn time of 25 minutes, before dropping again in October with a moderate index of 5. November and December then return to lower risks, emphasizing a UV Index of 2 and 1, respectively, allowing for longer safe exposure times of 45 minutes. To minimize the risk of UV-related harm, visitors and residents should take extra precautions during the high-risk months by wearing sunscreen, protective clothing, and limiting sun exposure during peak hours.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mountlake Terrace | 2 | 3 | 5 | 6 | 8 | 9 | 9 | 8 | 7 | 5 | 2 | 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 |