London Fog is a modern hybrid strain with an undocumented lineage. Breeders have not publicly confirmed the specific cross or the identity of its parents, with the exception of Pursang Haze, leaving the strain's genetic origins otherwise incomplete and open to debate. Due to this lack of documentation, there is no verified history regarding its primary breeder or development timeline, and the strain remains categorized as a modern variety rather than an heirloom or traditional landrace.

The sensory profile of London Fog is defined by a complex array of aromatics and flavors. Its terpene profile is dominated by terpinolene, followed in intensity by caryophyllene, myrcene, ocimene, limonene, beta-pinene, pinene, humulene, caryophyllene-oxide, linalool, nerolidol, camphene, isopulegol, gamma-terpinene, and alpha-terpinene. These compounds combine to create a distinct chemical signature. Consumers often report a high-yield harvest from this plant, which is considered of moderate cultivation difficulty and is capable of thriving in both indoor and outdoor environments, typically reaching maturity within a 60-day flowering window.

Regarding its chemical potency, the strain carries an estimated THC content of 29% and an estimated CBD concentration of 0%. Users frequently experience effects described as relaxed, happy, and uplifted, making the flower a common choice for managing stress, pain, and sleep-related concerns. While London Fog remains a notable presence in the modern market for its balanced therapeutic potential, there are no recorded instances of prominent offspring resulting from its use in further breeding programs.