UV Index
UV Index
Today's UV index in St. Catharines, Canada 
will be up to 7.3, 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: 2025-05-09
With St. Catharines's UV index reaching 7.3, 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.
St. Catharines has a UV index that varies throughout the year, reaching its highest levels of around 7 to 8 during summer months and dropping to 1 or 2 in winter. The city sees warmer, sunnier conditions in summer and cold, snowy weather in winter. Spring and fall have mild temperatures and moderate rainfall, with transitions between the two extremes. Compared to nearby cities like Toronto, St. Catharines tends to have slightly milder winters and warmer summers due to its proximity to Lake Ontario. In the wider Great Lakes region, it shares similar seasonal patterns but often experiences more lake-effect snow than areas farther from water.
See the UV index hour by hour for St. Catharines, along with the temperature and how cloudy it is. If the UV level is higher than moderate, it's best to avoid direct sunlight.