The answer is yes & no. The safety always depends on the weather and the coating you use.
For example in the rain, the coating will not be able to bond to the paintwork so therefore will not work as intended of for the period of time. The same is true with direct sunlight. On a hot summers day the panels may get hot, especially on darker vehicles so high spots are more likely.
We can make this safe however. In clear weather, under a gazebo or shelter when the car is out of direct sunlight, coatings are safe to use.
We personally use Pyramid Car Care Ceramic Coatings which have a 4 hour cure time. This essentially means the vehicle can get wet and be taken out in the rain after the four hour mark. This is definitely beneficial to mobile detailers to achieve the best results possible for our clients.
Essentially, if the weather is clear, the car is covered and the right products are used, ceramic coating outdoors is completely safe.
At TGS Detailing we only use safe methods and products for our clients to achieve the best results.