Do I need a climate-controlled storage unit?

It depends on what goes in. For papers and photos, the National Archives recommends keeping the temperature below 75°F and the humidity below 65%. Above that, mold grows and insects get busy. Air drier than 15% makes paper brittle.

The Archives says to keep family papers out of damp basements, garages and hot attics. A unit without climate control is basically a garage: hot in summer, cold in winter, damp in humid weather.

So documents, photos, artwork, and anything you'd be heartbroken to find moldy are worth climate control. Ask the facility, in writing, what temperature and humidity range the unit actually holds.

Keep papers you can't replace with you, not in storage.

Source: National Archives, How to Preserve Family Archives · Checked October 2026