Rain is not automatically bad for succulents. The risk depends on temperature, airflow, potting medium, plant health, and how long the plant stays wet afterward.
Short rain followed by good drying conditions may be fine, while prolonged wet weather can increase rot and fungal risk. Plants in dense media or low-airflow corners need more protection.
After rain, check whether water is trapped in rosettes, pots, or trays, and help the growing area dry safely.