Very similar thing here, I live in the Bay Area and have a flat, bright white roof. On an 85 degree summer day, it’s a wave of cool comfort to walk through the front door, and I pay nothing for it.
i live in an apartment building in LA with a vented attic and a flow-through design, as the building was built before air conditioners became popular. it’s cooler than ambient by a few degrees (haven’t rigorously measured it though) even without a white roof.