That 10.6mm is an average for the area,
"Thailand started a rainmaking project in the late 1950s. The first principle was to scatter sea salt to catch the humidity in the air and dry ice to condense the humidity to form clouds. The project took about ten years of experiments and refinement. The first field operations began in 1969 above Khao Yai National Park. Since then rain-making has been successfully applied throughout Thailand and neighbouring countries. On 12 October 2005 the European Patent Office granted to King Bhumibol Adulyadej the patent EP 1 491 088 Weather modification by royal rainmaking technology."
Source: wikipedia cloud seeding
"... research project, began as early as the 1830's ..."
source: metabunk History of Cloud Seeding...