In the winter time, keep your cacti and succulents in temperatures above freezing. They will go dormant and manage just fine in night time temperatures of 35° to 40°F. Your more tropical succulents like Adeniums, Euphorbias, Epiphyllums, Rhipsalis, Stapeliads, and Zygocactus
prefer warmer night time temperatures of between 50° and 60°F. However, if you harden them off by watering less in the fall, they will tolerate temperatures in the mid-thirties. Other less tropical succulents, like many cacti, Sempervivums, Sedums and Agaves can tolerate lower night time temperatures into the mid-twenties (or less) when they have been gradually acclimated to cold weather. In the summer, protect your cacti and succulents from extreme heat. If temperatures reach over 100°F, be sure to shade your plants and provide air circulation. When it is both humid and hot, it is particularly important to have good air circulation and careful watering to avoid fungus and rot problems.