Last updated: December 2, 2025
Understanding the UV Index is crucial for residents of Greenfield, United States, as it plays a vital role in protecting your skin from harmful ultraviolet rays. With summer temperatures often rising, the potential for sunburn and long-term skin health issues increases significantly. In this Cfa climate zone, Greenfield experiences varying levels of UV exposure throughout the day, peaking at a high of 10 between 1 PM and 2 PM. Staying informed about these UV levels can help you make safer choices when enjoying the beautiful outdoors, ensuring that your skin remains healthy and protected.
The UV Index is a dynamic measure of solar intensity throughout the day, peaking dramatically at 12:00 PM with a notable 9, reaching its zenith at 1:00 PM and 2:00 PM with a maximum value of 10. During this period, it's essential to protect your skin from harmful UV rays. Early morning hours remain quite low, peaking at just 1 by 08:00 AM, while by 10:00 AM the index climbs to 5. As the sun continues to rise, it climbs swiftly to 7 by 11:00 AM, making midday the crucial time for sunscreen and shade. As the afternoon wanes, the UV Index gradually decreases, falling back to 5 by 5:00 PM, and finally settling at 1 by 7:00 PM, signaling a safe return to outdoor activities. Stay vigilant and enjoy the sunshine safely!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 0 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 1 | low | 45 min |
| 10:00 | 2 | low | 45 min |
| 11:00 | 2 | low | 45 min |
| 12:00 | 3 | moderate | 30 min |
| 13:00 | 3 | moderate | 30 min |
| 14:00 | 2 | low | 45 min |
| 15:00 | 1 | low | 45 min |
| 16:00 | 1 | low | 45 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 0 | low | 45 min |
| 19:00 | 0 | low | 45 min |
Throughout the year, UV exposure changes significantly, with high-risk months identified from April to September, when the UV Index reaches notably high levels of 9 to 10. During these months, burn times are critically reduced to just 15 minutes, requiring extra caution. March marks the transition to higher UV levels, with an index of 7 and a 25-minute burn time, while January and February begin with a moderate UV Index of 3 to 5 and longer burn times of 30 minutes. As we move into the fall, UV exposure decreases, dropping to 4 in November and 3 in December. Visitors and residents are advised to protect their skin by wearing sunscreen, protective clothing, and seeking shade, particularly during high-risk months, to minimize the risk of UV-related skin damage.
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 |
| Greenfield | 3 | 5 | 7 | 9 | 10 | 10 | 10 | 9 | 8 | 6 | 4 | 3 |
| 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 |