Changes in climate and temperature are one of the main reasons condensation develops in import containers. This can happen when there is a shift from lower temperature to higher temperature. When the climate changes from cool to tropical, moisture surrounds the container. The difference in temperatures usually causes water vapor to condense within the import containers.
Condensation also can appear simply because there is moisture already inside a container before it's loaded and shipped. If the temperature rises during transport, condensation likely will occur. That's why it's important for exporters to inspect shipping containers for water build-up before sending them out.
Humidity inside an import container can create the conditions for condensation. Sometimes humidity is formed because of the packaging materials on products within the container. Other times it comes from small puddles on the bottom of the container. Often that trapped moisture creates humid conditions that lead to condensation.
Damaged import containers also can cause condensation. Older containers with a lot of usage can develop small holes. As a result, any contact with inclement weather will cause moisture to seep in.