Depending on how cold it gets, you might be better to store during the winter with a low pressure fill rather than full.
Even though cylinder compressors have moisture separators, there is still some moisture present in the cylinder air. The higher the pressure, the higher the dewpoint. This is clearly a problem for storing steel cylinders, but still undesirable for aluminum tanks. Here is a recent thread that touches on the subject:
Proper tank storage
I just checked my last test results for my 30+ year old compressor, and the moisture content was 3.7 ppmv which has a dewpoint of -90°F at ambient pressure, but that comes up to about -10°F at 3000 psi. That is important to know when storing a steel cylinder in an unheated garage during a Chicago winter. What I don't know is what that moisture content is in other filling stations, or if it would vary depending on the ambient humidity at the time of the fill. (I suspect it would)
Addendum: I just checked several test results from years past. Looks like anything lower than 3.4ppmv is not quantified, and just listed as <3.4ppmv, so that appears to be the low end of moisture content in compressor tests. It does look like that metric varies depending on when it is measured, and the highest I had was 13.1ppmv about 4 1/2 years ago, which has a dewpoint of +15°F at 3000 psi, and +18°F at 3500 psi. So yeah, don't store tanks 100% full in unheated areas in cold climates.