South Simcoe Forecast for Monday April 22 New Tecumseth, ON, Canada / FM92 South Simcoe Today Adrianne Proceviat Apr 22, 2024 | 6:34 AM Nathalie / CC Happy Earth Day! Sunny today… High 14. A few cloudy periods this evening… Low 7. Mainly cloudy tomorrow… Showers expected in the morning… Should dry up by the afternoon… High 15.