Alexandra

Alexandra has an inland, continental climate that contributes to extreme temperatures during winter and summer. It is not unusual for overnight temperatures in winter to reach -10°C for several nights in a row. Strong temperature inversions result during periods of calm, still weather and clear skies, forming overnight and into the morning. An inversion layer occurs as the ground rapidly cools and so does the air close to it. This cold dense air is trapped at the surface below warmer and more buoyant air. These events can also cause PM₁₀ emissions to become trapped near the ground and become more concentrated.

The main source of PM₁₀ in Alexandra is from domestic heating appliances. PM₁₀ concentrations peak during winter mornings and evenings, times of the day when it is coldest, and when there is little to no wind. Daily PM₁₀ concentrations regularly exceed the national guidelines from May through August but are quite low during the rest of the year.