(SOUTHERN COLORADO) — Southern Colorado was covered in fog over the weekend, and while it’s not an uncommon phenomenon, you may be wondering how fog forms in the first place?

There are several types of fog: radiational fog, advection fog, and even hail fog. But for the purposes of this article we are going to talk about the type of fog that hit our area: radiation fog.

Radiation fog occurs overnight with clear skies and calm winds happen and there is some moist air present. Overnight, the clear skies allow heat from the day to radiate into space, and as the earth’s surface continues to cool, the cooler temperatures allow the air to become saturated, humidity will reach 100 percent and fog will form.