Environment Canada has issued a yellow level frost advisory for Toronto, Peel and Halton regions as the temperature is expected to drop to near the freezing mark on Monday night.“Patchy frost is expected to develop tonight into Tuesday morning, particularly for areas north of the 401 corridor,” the national weather agency said in its alert.The high for Monday on election day is forecasted to be high of 16 C with sunny breaks and a slight chance of showers. However, the temperature will drop to a low of near 3-4 C.The cooler air is expected to persist into Tuesday before the GTA bounces back again to mild conditions on Wednesday through the weekend.A high of 10 C is in store for Tuesday with a low near 2 C. On Wednesday, the temperature is expected to reach 14 C but could soar to 20 C by Thursday.The mercury is forecasted to reach 16 C on Friday, and looking ahead to Halloween, the current forecast indicates will be mild and dry.Click here for the current and extended forecast.