Freezing temperatures and patchy frost expected tonight with widespread frost Monday night.
A very cold air mass moving over the regions will give low temperatures of zero or minus one tonight across the regions. There will initially be very windy conditions this evening as the temperatures drop however frost in the form of ice crystals forming on the ground will be only patchy due to the persistent winds. The ground temperatures will eventually reach the freezing mark late this evening or by midnight and even though light westerly breeze may limit frost from forming there is still the significant threat to sensitive plants. There may also be a centimetre or two of snowfall accumulation through Grey-Bruce, Barrie and east of Georgian Bay rapidly bringing the ground temperatures to the freezing mark. On Monday night a classic plant-killing widespread frost will form on the ground due to the cold air in place giving freezing temperatures and due to winds becoming light under clear skies.
Refer to your local public forecast for further details.