I really will not encourage that evening watering Adam. We also get triple digit here, and I do not do that. With the other types of plants, they can benefit with evening watering, since their stomates are also open during daytime. But with succulents and cacti, though they do the CAM exchange at night, once there is moisture in the air, they will utilize that air moisture first before they use up their stash, so they may use the moisture in the soil, but they do not drink it all up that night, so roots might end up sitting too moist far longer.
Fiat, we all learn everyday..I was negligent too before, but I am adjusting my watering habits too, as season changes, as conditions change. And I have killed my fair share of succulents too.
As to which is cacti and which are succulents...here is something to remember...all cacti are succulents, but not all succulents are cacti. Knowing what type of succulent you have will also help you adjust your watering regimen. There are tropical, desert and alpine succulents, then knowing if they have dormancy periods. Hey I use to successfully kill Plumerias...finally got my bearings right I think..after 3 years
My existing nemesis are Pleiospilos nelli and Lithops..just cannot get my timing right with these cute succulents..but I will keep trying!
Something I have learned during these past few years, most cacti, they can take a bit more frequent watering, if grown outdoors, in full sun, in full heat. It is their active growing time. Indoor grown cacti, have to keep them a bit more drier, since it takes longer to dry. But during cold season, keep them much more drier, they have adapted to slow down growth to no growth at all during very cold temps, so they have no need for any extra moisture uptake. But whichever watering manner or frequency done, very important, keep their media very well draining.
