Yes I believe spirea are deciduous everywhere. There may be a variety I am not aware of that is evergreen, but I don't know of one. I just had this conversation with my "everything needs to be evergreen" neighbor, who is finally coming around. Evergreens are important, don't get me wrong, but the landscape would be so boring if you eliminate things because they are deciduous. That is aprt of the wonder of spring-- new life/leaves and not to mention without deciduous shrubs you lose out on autumn color, just some thoughts.

I have Anthony Waterer, Magic Carpet and Golden Elf and all are deciduous for me. The differing colors during leaf emergence and maturity in spring for many Spireas, is not to be missed.

I have only one shrub, a small Spiraea japonica 'Shirobana'(white, pink & rose flowers) and it is deciduous. I have seen references that some species or cultivars are semi-evergreen, whatever that means. Mine is planted in an area with other deciduous shrubs and trees, flowering Quince, Native Azaleas, Japanese Maples, etc, but they are overshadowed by a huge evergreen Holly shrub that is covered with red berries in the winter, so the bare limbs are barely noticeable. This past winter, when we had a few centimeters of snow, hundred of Robins converged upon the Holly and picked it clean. The berries they dropped on the ground were cleaned up the following day. A few Rufous-sided Towhee's and Cedar-waxwings tried to join in, but were nosed-out(or should I say; beaked-out). It was a sideshow that I had never seen and probably won't again.
Rb