Very little mushroom drying is done in the United States. Specialty mushrooms are sold only to the fresh market. Natural perils that can affect mushroom yields are excessive rain, excessive heat and humidity, excessive cold, high winds, and other seasonal factors. Mushroom production occurs indoors and is largely insulated from outside weather conditions. On occasion, however, outside weather makes controlling the inside climate difficult.
Autumn is an especially difficult season for mushroom growers.
Because the weather is more predictable during the winter and summer, it is easier for growers to control heating, cooling, and moisture levels than during autumn. In autumn, sudden temperature changes increase the difficulty of controlling conditions inside the mushroom house. Inaccurate temperature and humidity controls can cause discolored or blotched mushrooms, which would be unmarketable in the fresh market. Weather conditions can also interfere with compost production, particularly phase 1 composting, delaying the processing or resulting in inferior compost. Brown outs, total power outages, or equipment breakage can interfere with controlling the mushroom house climate.