South Simcoe Forecast for Thursday March 28 New Tecumseth, ON, Canada / FM92 South Simcoe Today Adrianne Proceviat Mar 28, 2024 | 6:29 AM Mix of sun and cloud today… High of 7 degrees. Partly cloudy this evening… Low minus 4. Cloudy with the slight chance of flurries tomorrow… High plus 4.