Last updated: July 2, 2025
In Billings, Montana, understanding the UV Index is crucial for maintaining skin health and preventing sunburn, especially during the peak summer months. Awareness of UV levels helps residents and visitors make informed decisions about sun exposure, effectively protecting themselves from harmful rays. With Billings' Cfa climate, characterized by hot summers and varying UV exposure throughout the day, it's important to recognize that midday can bring a high UV Index of up to 11—indicating an increased risk of harm from unprotected sun exposure. Stay informed and safeguard your skin while enjoying all the outdoor activities our beautiful city has to offer!
The UV Index for the day starts gently, with values peaking at 1 from 7:00 AM to 8:00 AM. As the sun rises higher, the index escalates, reaching 3 by 9:00 AM. A significant surge occurs between 10:00 AM and 2:00 PM, where it escalates dramatically, peaking at a striking 11 from 1:00 PM to 2:00 PM—a clear indication to seek shade and protect your skin. The afternoon sees a gradual decline, with figures dropping to 10 at 3:00 PM, then to 7 at 4:00 PM. As the day winds down, the UV Index returns to safer levels, resting at 1 by 7:00 PM. Keep in mind, high UV levels call for precautions, especially in the midday sun!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 11 | extreme | 10 min |
| 14:00 | 11 | extreme | 10 min |
| 15:00 | 10 | very high | 15 min |
| 16:00 | 7 | high | 25 min |
| 17:00 | 5 | moderate | 30 min |
| 18:00 | 3 | moderate | 30 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, UV exposure varies significantly, with high-risk months primarily occurring from April to September. The UV Index peaks during June and July at 11, indicating an extreme risk of harm from unprotected sun exposure, where burn time is as short as 10 minutes. Early spring begins with moderate levels in January (UV Index 4) and escalates to very high levels in April (UV Index 10). As the summer progresses, residents and visitors should be especially cautious during peak hours, practicing sun safety measures such as wearing sunscreen, protective clothing, and seeking shade to reduce risk. As autumn approaches, UV levels decrease, dropping back to moderate levels by December, making it safer for prolonged outdoor activities.
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 |
| Billings | 4 | 6 | 7 | 10 | 10 | 11 | 11 | 10 | 9 | 7 | 5 | 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 |