Onions like to live in cool, dark places that have temperatures between 45 and 55 degrees F. If you have conditions like this in your home you could get two or even three months when stored in these cool dry places.
Depending on where you live you could have a cellar, basement, or garage with these conditions. However, for those of us who do not we are better off strong onions within our refrigerator for the longest life we can get out of them.