Residents of St. Thomas can expect a chilly start to the week before a shift toward warmer weather brings temperatures well above seasonal norms by Thursday. According to Environment Canada, there are no active weather alerts for the area as of April 19, 2026.
Sunday will be mainly cloudy with a high of 7°C, accompanied by northwest winds gusting up to 50 km/h and a 30 percent chance of showers. Conditions will turn colder tonight as temperatures drop to -2°C, with a wind chill of minus 7 and a 70 percent chance of flurries. The Weather Network expects 2 to 4 mm of rain and less than 1 cm of snow accumulation by the time the system moves through.
Monday remains cold with a high of only 2°C and a morning wind chill reaching minus 8. A 70 percent chance of flurries is expected to continue through the morning hours.
A significant warming trend is set to begin Tuesday, with temperatures climbing to 13°C. The mercury will continue to rise to 16°C on Wednesday, reaching a pleasant 21°C by Thursday. This expected high for Thursday is well above the seasonal normal of 14°C for this time of year in St. Thomas.
