Last updated: June 2, 2025
Understanding the UV Index in Gretna, United States is crucial for safeguarding your skin and overall health. With the peak UV levels reaching a striking 11 during midday hours, awareness of these fluctuations can help residents and visitors alike prevent sunburn and long-term skin damage. In this Cfa climate zone, characterized by hot summers, the risk of overexposure to harmful UV rays increases, making it essential to monitor UV levels closely and take protective measures. Stay informed and enjoy the sunshine safely!
The UV Index throughout the day exhibits a remarkable peak, beginning at a low 1 in the early hours, gradually rising to 5 by 10:00. As the sun reaches its zenith, the index soars to an impressive 10 at 12:00, hitting a maximum of 11 from 13:00 to 14:00. This intense exposure makes midday the most critical time for sun protection. As the afternoon progresses, the index begins to dip, falling to 7 at 16:00, and winding down to a gentle 3 by 18:00. By 19:00, the UV Index drops back to 1, signaling a return to safer sun conditions. Planning outdoor activities? Make sure to take precautions from late morning to mid-afternoon, when the sun’s rays are most powerful!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 2 | low | 45 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 11 | extreme | 10 min |
| 15:00 | 10 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 5 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
As the seasons change, so too does the UV Index, which significantly impacts exposure and burn time. From January's moderate UV Index of 5 with a burn time of 30 minutes, we enter a period of increasing risk; February through April sees a jump into the very high category, consistently reaching 8 to 10. The height of summer marks the peak danger, with May through July classified as extreme (UV Index 11 to 12), where just 10 minutes of exposure can lead to burns. August returns to an extreme level before tapering off in September and October to a very high index of 10 and 8 respectively. November and December bring a return to high and moderate levels, with more forgiving burn times of 25 and 30 minutes. Visitors and residents are advised to take necessary precautions, particularly during the high-risk months of February through October, wearing sunscreen, protective clothing, and seeking shade, especially during peak sunlight hours.
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 |
| Gretna | 5 | 8 | 9 | 10 | 11 | 11 | 12 | 11 | 10 | 8 | 6 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |