Can a ceramic coating be done outside?
Ceramic coatings shouldn't be applied outside for a number of important reasons. You do not want any dust settling on the car, before or during the application process. Perhaps more essential, you have a narrow window in which to remove the excess, which is a fairly comfortable window under controlled conditions. However, if the car is too hot under the sun, if it's windy, things could go wrong very quickly. You only get one shot at this, so rain, humidity, cold, pigeons and any number of factors could complicate the process, and ruin your day.
Application of ceramic coatings needs to be done inside, undercover, in a stable temperature with good lighting.