Aloha Keith,
Chances are, year round storage in our intense sun is going to put love handles on your boats hull. That plastic will cook and cool down every single day, regardless of the cover used. Shade is the key.
You could devise a canvas bimini shade tarp for it, if they would allow that on base, but it could blow away or damage something, left unattended.
The good news is that the Hobie cradles should be more forgiving than other kayak saddles (as far as deforming the hull) and you might be able to use pads or blankets to cushion the load.
Generally, it is advisable to store the yak (covered) on its top or side for long longer periods.
Or just take it out on the water every day.
Problem solved.