Our weather forecast for next week (Edit: should read week after next - I cannot keep things straight anymore!) predicts high temperatures in the 105F to 108F (41C to 42C) range. I am then going to switch to my summer watering regimen for my cacti growing under 30% shade cloth in small plastic pots: a soaking every evening at dusk using a one gallon Haws watering can except for Thunderstorm days. I have been doing this for years and my plants flourish under it and love it.

James

Thanks for the watering info James, that is great info. Here in Mesa we are looking at 105 on Tuesday...

I wish I had time to get all my plants in pots watered that frequently, I am sure they would really like that. I am hoping to get to about twice per week for all potted plants and once per week for the stuff in the ground. My seedlings are going to get water every day from now on up from every other day.

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.