Last updated: June 2, 2025
In Ontario, United States, being aware of the UV Index is crucial for maintaining your skin health and preventing sunburn. With summer days bringing increased UV exposure often peaking around midday at levels reaching 10, understanding the UV levels can help you make informed decisions about sun protection. The climate here, characterized as Dfb, experiences a wide range of seasonal changes, but during warmer months, the risk of harmful UV radiation is significant. Stay informed to enjoy the sun safely and keep your skin protected!
As the sun rises, the UV Index begins its steady ascent, starting at a mild 1 at 7:00 AM. By 8:00 AM, it reaches 2, hinting at the day ahead. As we approach mid-morning, the intensity climbs to 3 by 9:00 AM and then dramatically spikes to 5 at 10:00 AM. The real peak occurs between 12:00 PM and 2:00 PM, where the index soars to a whopping 10, indicating strong sun exposure. This midday intensity begins to taper off by 3:00 PM, as it drops to 9, and continues to slide through the late afternoon, ending the day at 1 by 7:00 PM. It's crucial to stay protected during those peak hours to enjoy the sun safely!
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 | 10 | very high | 15 min |
14:00 | 10 | very high | 15 min |
15:00 | 9 | 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, peaking in the late spring and summer months. April to August represent the high-risk period, with UV Index values reaching 10; indicating a very high exposure category and a burn time as short as 15 minutes. Visitors and residents should exercise caution and take protective measures, such as wearing sunscreen and protective clothing during these months. In contrast, January and December have moderate and low UV levels, respectively, with longer burn times of 30 to 45 minutes. Action is still advisable during these months, but the intensity is notably lower, allowing for safer outdoor activities. Overall, awareness of seasonal UV changes is essential for protecting skin health year-round.
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 |
Ontario | 3 | 5 | 6 | 8 | 10 | 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 |