This is interesting from my comparatively lazy perspective. I water my seedling cacti twice a week year round, without altering the frequency except as convenience or occasional rainfall may dictate.

The adults in pots get weekly water, the plants in the public garden get water every 2 weeks. The plants in the park get zero water when established.
For some perspective, we have not been above 70° for the past 3 weeks thanks to some pretty heavy fog. The air temperature here is very close to the ocean temperature, which is unusually cold here thanks to coastal upwelling. So obviously very different from southern AZ.
I am somewhat in awe of you desert dwelling cactus growers who have learned to adapt to such extreme conditions, just like your plants.