Last updated: July 2, 2025
In Hannibal, United States, awareness of the UV Index is crucial for safeguarding your skin and overall health. Understanding UV levels is essential not only for preventing painful sunburns but also for reducing long-term risks of skin damage and related conditions. With Hannibal's Dfb climate—characterized by cold winters and warm summers—the UV exposure risks can increase significantly, especially during peak hours when the UV Index reaches levels as high as 9 around noon. Stay informed and protect your skin by checking the UV Index regularly, ensuring a safe and enjoyable time outdoors.
The UV Index for the day showcases a notable rise in intensity as the sun climbs higher in the sky. Starting at a low of 1 at 7:00 AM, the index gradually increases to a moderate level of 3 by 9:00 AM. However, from 10:00 AM onward, things heat up significantly, peaking at a scorching 9 from noon to 2:00 PM. As the afternoon progresses, the UV Index gradually dips back to a friendly 3 by 5:00 PM, then descends further to 1 by the time evening sets in. This pattern underscores the importance of sun protection during peak hours, especially between 11:00 AM and 2:00 PM, when UV levels are at their highest.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 7 | high | 25 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 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
As the seasons change, the UV Index reveals significant fluctuations in sun exposure risk. Winter months (January and February) have moderate UV levels with an index of 3 to 4, leading to a burn time of approximately 30 minutes. Transitioning into spring, the UV Index rises sharply: March reaches a high of 6, and by April it soars to 8, signaling the start of very high risk months with a burn time reduced to 15 minutes. The summer months (May through August) maintain this high threat level, peaking at 10 in June, necessitating extra precautions for outdoor activities. As September and October approach, the UV Index decreases to 7 and 6, respectively, still indicating a high risk for 25 minutes of safe sun exposure. November and December see a return to moderate and low levels for UV exposure, with longer burn times of 30 to 45 minutes. Residents and visitors are advised to take protective measures, especially from April to August, including wearing sunscreen, protective clothing, and limiting time in direct sunlight during peak hours.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Hannibal | 3 | 4 | 6 | 8 | 9 | 10 | 9 | 9 | 7 | 6 | 3 | 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 |