Botrytis infections are favored by cool and humid conditions, and are most common during rainy spring and summer weather…
— Urban Garden Magazine

A person who has been exposed to black mold may have the following mold symptoms: difficulty breathing, they may experience headaches, coughing, nausea, memory loss, dizziness, asthma, bronchitis, urinary tract infections, and over time they may even experience infertility… using a dehumidifier can control the humidity that attracts the dangerous fungus…
— Black Mold Removal Guide

There is no practical way to eliminate all molds and mold spores in the indoor environment; the way to control indoor mold growth is to control moisture.
— E.P.A.

Black molds grow in moist warm soil. Florida’s tropical climate, with its heat and humidity, creates a perfect setting for fungi to grow and thrive.
— University of Florida

Grey mold is favoured by shade or dense foliage in the bed and extended periods of excessive moisture. The likelihood of infection is increased by cool spring and summer temperatures and high humidity from frost control techniques, general irrigation and natural rainfall.
— Manitoba Government

Such infections are most common in well protected areas of the plant, where the humidity is high and air movement is poor.
— University of Illinois

Gray mold is caused by the fungus Botrytis cinerea… Temperatures of 70 to 80 F and ample moisture favor the disease. Frequent irrigation and/or rain promote disease development.
— Purdue University

Botrytis loves warm, and humid (50% or over humidity) conditions. Lowering humidity will slow and stop spore germination.
— Green Passion