It was a chilly start to Wednesday as many woke up to frost.
Frost usually forms on clear nights with a light wind and temperatures near freezing.
If there is enough moisture in the air, the water molecules within the air will slow down and that moisture will freeze onto plants, the ground and to our cars, what we call frost.
A heavy frost is possible with more moisture in the air, less moisture means a lighter frost.
But the air temperature doesn’t necessarily need to drop down to the freezing point of 32 degrees.
We can still get frost with temperatures above freezing, it’s all about how temperature is measure.
Official temperatures recordings are measured inside a Stevenson box, now these are about 2 meters above the ground, roughly 6 and a half feet above the ground, so that's where most of our heads are.
When cold air comes on in it's measured at that height. Now the coldest of the cold air is more dense than warm air, so that coldest air is going to sink down to the ground.
So while the temperature where our heads are may read above the freezing mark, the temperatures at the ground is going to be even colder, closer to freezing which could eventually create some frost .
Temperatures at the ground can be anywhere from 5 to even 10 degrees colder than just above the surface, where the official morning low temperatures are recorded.