St. Marys, IA Weather
St. Marys, IA climate is warm during summer when temperatures tend to be in the 70's and very cold during winter when temperatures tend to be in the 20's.
The warmest month of the year is July with an average maximum temperature of 9.99 degrees Fahrenheit, while the coldest month of the year is January with an average minimum temperature of 9.50 degrees Fahrenheit.
Temperature variations between night and day tend to be moderate during summer with a difference that can reach 22 degrees Fahrenheit, and moderate during winter with an average difference of 20 degrees Fahrenheit.
The annual average precipitation at St. Marys is 9.99 Inches. Rainfall in is fairly evenly distributed throughout the year. The wettest month of the year is June with an average rainfall of 4.60 Inches.