Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Phoenix, United States, where the sun shines intensely for much of the year. With daily UV levels soaring to 10 or higher during peak hours, awareness of these readings can play a significant role in preventing sunburns and protecting skin health. Given Phoenix's arid climate and abundant sunshine, the risks associated with prolonged sun exposure are heightened, making it essential to stay informed about UV levels. By knowing when to seek shade and apply sunscreen, you can enjoy the vibrant outdoors while keeping your skin safe from harmful UV rays.
The hourly UV Index data reveals a dynamic shift in sun intensity throughout the day, starting from a gentle 1 at 07:00, ideal for morning strolls. As the sun rises higher, the index escalates, peaking at a potent 10 between 12:00 and 13:00. This mid-day surge emphasizes the need for sunscreen and protective gear, as the risk of harm from UV rays increases significantly. By 15:00, the index begins to decline, settling at 7 before tapering off further to a mere 1 by 19:00, signaling a safe reprieve for evening outdoor activities. Stay aware and protect your skin during those peak hours!
| 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 | 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 | 2 | 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Phoenix | 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 |