Relative Humidity Rh

Relative humidity (RH) is not a terpene, but rather an environmental factor that significantly influences terpene expression, preservation, and stability in cannabis cultivation and storage. RH measurements indicate the amount of moisture present in air relative to the maximum amount air can hold at a given temperature, typically expressed as a percentage. During growing cycles, RH levels between 40–60% are commonly associated with optimal terpene biosynthesis, while improper humidity can degrade volatile compounds post-harvest. Storage at 55–62% RH is frequently recommended to prevent both mold development and excessive terpene volatilization. Understanding RH is essential for breeders and cultivators seeking to preserve genetic expression and aromatic profiles across generations.

Breeders working in controlled environments carefully monitor RH to ensure stable terpene phenotype expression and consistent cannabinoid/terpene ratios across seed lots. Proper humidity management during flowering and curing is critical for maintaining the genetic terpene signature that distinguishes cultivars and strain families.