To clarify my comment about attic insulation, if the insulation is on the floor of the attic (either batts or blown-in), the attic space itself will not be insulated, and it could become very warm in summer and cold in winter. Depending on where you live, of course.

On the other hand, if the insulation is on the inside surface of the roof itself, and the attic is finished living space, it might remain at moderate temperature.

As a serious record collector myself, I would not consider storing them in my attic.