Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Cortez, United States, where the sun’s rays can be surprisingly intense. With a climate characterized by low humidity and clear skies typical of the BSk zone, UV levels can soar, especially from late morning to early afternoon, peaking at 12 around 1 PM. Awareness of these levels is essential not only to prevent painful sunburns but also to protect long-term skin health. Staying informed about UV exposure is your best defense against skin damage, enabling you to enjoy Cortez’s beautiful outdoors while keeping your skin safe.
The UV Index rises sharply as the day unfolds, starting gently at 1 by 7:00 AM. As the sun climbs higher, it reaches 2 by 8:00 AM and then jumps to 4 by 9:00 AM. The intensity peaks around midday, hitting a striking 11 at 12:00 PM, followed closely by a maximum of 12 from 1:00 PM to 2:00 PM. In the afternoon, the index begins to decline, dropping to 10 by 3:00 PM and further down to 5 by 5:00 PM. As daylight wanes, the value lowers to 1 by 7:00 PM, indicating a rapid decrease in UV exposure. This cyclical pattern highlights the importance of sun protection during peak hours, especially between 11:00 AM and 2:00 PM when the UV Index is highest.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 4 | moderate | 30 min |
| 10:00 | 6 | high | 25 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 11 | extreme | 10 min |
| 13:00 | 12 | extreme | 10 min |
| 14:00 | 12 | extreme | 10 min |
| 15:00 | 10 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 5 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index exhibits significant seasonal changes, peaking during the summer months. High-risk months for UV exposure include March through August, with the highest values recorded in June (UV Index 13) and July (UV Index 12), classified as extreme exposure, allowing only 10 minutes of burn time with no protection. As spring transitions to summer, caution should be exercised, especially in April (UV Index 11) and May (UV Index 12), where exposure is still deemed extreme. In contrast, the UV levels decrease significantly in the fall and winter months, dropping to a moderate level in December (UV Index 4). It is advisable for visitors and residents to take protective measures, such as wearing sunscreen, hats, and sunglasses, particularly from March through August, to mitigate the risks associated with high UV exposure.
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 |
| Cortez | 5 | 7 | 9 | 11 | 12 | 13 | 12 | 11 | 10 | 8 | 6 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |