Under what conditions do inversions typically occur?

Inversions typically occur when wind is calm and the air at ground level is cooler than the air above. This situation leads to a stable atmosphere where the cooler air becomes trapped beneath a layer of warmer air. Inversions are significant because they can prevent pollutants from dispersing, leading to poor air quality.

When the air at ground level is cooler, it cannot rise through the warmer air above, creating a layer that acts as a cap for any air that wants to rise. This layer can also lead to the formation of fog or low clouds, as moisture in the cooler air may condense. The calm winds further contribute to this phenomenon because without sufficient wind to mix the air, the stratification remains intact.

The other conditions listed would not typically lead to inversions, such as strong winds or high temperatures, which promote mixing and prevent an inversion from occurring.