Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Romeoville, United States, where sun exposure can pose significant risks to skin health. With a Dfa climate characterized by hot summers and varying ultraviolet radiation levels, being aware of the UV Index helps prevent sunburn and long-term skin damage. During peak hours, particularly around noon to early afternoon, UV levels soar to a maximum of 9, signaling a critical time for protection. By staying informed about daily UV forecasts, you can enjoy the sunshine while safeguarding your skin against its harmful effects.
As the sun rises, the UV Index starts off relatively low, peaking at 1 at 7:00 AM. By 8:00 AM, it gently climbs to 2, but it’s not until 9:00 AM that the intensity begins to gather real momentum, reaching 4. The index rises sharply as the day progresses, hitting 6 by 10:00 AM, and then escalating to a striking 8 at 11:00 AM. The maximum intensity occurs at 12:00 PM and 1:00 PM, where it levels off at a high 9. This peak is maintained through 2:00 PM, after which the UV Index begins its descent, dropping to 7 at 3:00 PM, 5 at 4:00 PM, and further declining to 3 by 5:00 PM. By the evening, it gently falls back to 1 at both 6:00 PM and 7:00 PM, signaling a significant reduction in sun exposure. Overall, it's a day where protection from UV radiation is essential during 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 | 9 | very high | 15 min |
| 13:00 | 9 | 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 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 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 |
| Romeoville | 3 | 4 | 6 | 8 | 9 | 10 | 10 | 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 |