Inversion occurs when a warm layer of air acts ... clear skies which increase the rate of cooling near the surface, longer nights which means the ground stays cooler and the sun angle.

This is known as surface temperature inversion. It explains why frost is more common and extensive in low-lying areas. Areas where frost forms due to cold air trapped against the ground or against ...

“A temperature inversion in the valley is helping to trap pollutants at the surface and may cause poor air quality at times,” Bayern said. “An inversion is when cold air pools at the ...