Michigan State University Extension
Preserving Food Safely - 01600533
Michigan weather does not lend itself to drying fruits and vegetables in the sun. Spoilage--souring or molding--will probably occur before drying is achieved.
Sun drying requires temperatures over 98 degrees Fahrenheit and low relative humidity such as conditions found in the Southwestern United States. For example, in Phoenix, Arizona, the average maximum temperature in August is 102 degrees Fahrenheit, the humidity bottoms out at 24 percent, and 17 of the 31 days are clear.
Typical Michigan weather varies greatly from these ideal drying conditions. In Lansing, the average maximum temperature in August is 81 degrees Fahrenheit, the humidity at the driest time of the day averages 56 percent, and only 10 days are clear.