ULN2003A: Environment ESD

We designed environment  product  like sensor, that communication line is using signal transmission in parallel signal through 15 meter. In Indian environment early morning it’s not working proper but after 9 AM (December and January) it’s working proper. What is issue exalt we know, the problem is humanity if night cooling is formed to humanity ones sun light is get it’s problem is rising. And also exactly we don’t know which components are affected like amplifier, microcontroller, buffer, line drive. How can we control the environment in our design and PCB. Kindly give any solution.