UV Index
UV Index
Today's UV index in Hamilton, Canada 
will be up to 7.5, indicating a high level of sun exposure for the average person. Check our tips for today to make sure you're safe in the sun.
Last checked: 2025-06-01
With Hamilton's UV index reaching 7.5, protect your skin from harm by staying in shade, wearing protective clothing, and applying SPF 30+ sunscreen every 2 hours, especially between 10 a.m. and 4 p.m. when UV rays are strongest.
Hamilton's UV index varies seasonally, reaching moderate to high levels during summer months and staying low during fall and winter. The peak UV index typically occurs in June and July.
Hamilton experiences four distinct seasons: cold, snowy winters; warm, humid summers; and mild springs and falls with variable rainfall. Snowfall is common from December to March, while summer temperatures often range from 20 to 30°C (68 to 86°F).
Compared to the wider Ontario region, Hamilton has a slightly milder climate due to its location near Lake Ontario, which moderates temperatures. Neighboring cities like Toronto have similar weather but may experience slightly warmer summers and colder winters.
See the UV index hour by hour for Hamilton, along with the temperature and how cloudy it is. If the UV level is higher than moderate, it's best to avoid direct sunlight.