Residents in Cornwall, Ontario, should prepare for a chilly start to the week as temperatures drop below freezing tonight, April 19, 2026. Environment Canada is forecasting an overnight low of minus 5 degrees, with wind chill values making it feel closer to minus 11 degrees due to steady west winds.
While the weather will remain cold, there are currently no official weather alerts in effect for the area. Residents should prepare for even colder conditions on Monday night, with temperatures forecasted to dip to minus 6 degrees.
According to Health Canada, cold-related injuries can happen at near-freezing temperatures, so those planning to be outdoors should dress in layers and take precautions. This cold snap is a typical part of the spring transition in the region, where frost can occasionally occur well into May.
The good news for the community is that warmer weather is on the way. Temperatures are expected to climb steadily throughout the week, reaching a high of 15 degrees by Thursday and 16 degrees by Friday, marking a return to more seasonal April norms.
Local weather patterns in Cornwall are often influenced by the nearby St. Lawrence River. The water acts as a moderator for temperatures along the shoreline, though it also contributes to the cloud cover and precipitation patterns frequently seen during this time of year.
