Last updated: June 2, 2025
Understanding the UV Index is crucial for residents and visitors in Eastham, Massachusetts, to effectively manage sun exposure and protect their skin health. With UV levels reaching a maximum of 10 during peak hours, the risk of sunburn can escalate quickly, making awareness essential for prevention. This coastal town, characterized by its Cfa climate, experiences a diverse range of weather conditions that can influence UV exposure. Knowing the UV Index helps ensure you enjoy the beautiful outdoors while safeguarding your skin from harmful effects. Stay informed and enjoy the sun responsibly!
As the sun rises, the UV Index begins to climb, starting at a modest 1 by 7:00 AM. By 8:00 AM, it has tripled, reaching 3, and continues its ascent to 4 at 9:00 AM. The peak intensity hits between 12:00 PM and 1:00 PM, where the UV Index soars to an intense 10—an indication of strong sun exposure. The afternoon sees a gradual decline, with values of 9 at 2:00 PM and 7 by 3:00 PM, showing that even later in the day, caution is advised. As the sun begins to set, the UV Index drops back down to 1 by 6:00 PM, making the daylight hours the most critical for sun protection. Stay safe and smart under the sun!
| 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 | 7 | high | 25 min |
| 11:00 | 8 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 10 | 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 | 3 | moderate | 30 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV index levels fluctuate significantly, with notable increases during the warmer months. January and February experience a moderate UV index of 3 and 4, allowing for a 30-minute burn time under the sun. As the seasons transition into March and onward, the risk escalates, peaking in June and July with a maximum UV index of 10—classifying these months as high-risk. During these summer months, individuals are advised to limit sun exposure to just 15 minutes to prevent skin damage. The trend continues with August and September maintaining high levels (UV index of 9 and 8 respectively) before tapering off in October (UV index 6) and returning to moderate levels in November and December (UV index of 4 and 2). Residents and visitors should prioritize sun protection, especially during the peak months of April through September.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Eastham | 3 | 4 | 6 | 8 | 9 | 10 | 10 | 9 | 8 | 6 | 4 | 2 |
| 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 |