South Simcoe Forecast for Friday April 26 New Tecumseth, ON, Canada / FM92 South Simcoe Today Adrianne Proceviat Apr 26, 2024 | 6:41 AM Chris Urbanowicz / CC Sunshine today… High 14. Cloudy periods this evening… Low plus 4. Cloudy with periods of rain tomorrow… Risk of a thunderstorm… High 15.