What is usually the most abundant outdoor mold?

Cladosporium is recognized as the most abundant outdoor mold, particularly in temperate climates. This fungus thrives in various outdoor environments, especially on decaying plant matter, wood, and soil. The spores of Cladosporium are easily airborne and can travel great distances, contributing to its high prevalence.

In many regions, Cladosporium can be found in large quantities during specific seasons, particularly in the fall and spring, when conditions for fungal growth are optimal—when temperatures are moderate and humidity levels are sufficient to support spore development and dispersal.

While other molds like Aspergillus, Penicillium, and Rhizopus are also significant in various contexts and may be associated with different environmental niches, they do not reach the same levels of abundance in outdoor environments as Cladosporium. Therefore, it stands out as the primary mold encountered in outdoor air samples, highlighting its ecological prevalence.