A monitoring and response system is provided for monitoring and responding to environmental conditions at one or more sites. The monitoring system includes a plurality of base units, each base unit including at least a processor and a plurality of sensors configured to monitor environmental conditions at the site(s). A central controller is in communication with the base processors at the plurality of base units and is configured to receive and process sensor information from the base units. Base units are configured to be modular and contain customizable, swappable combinations of sensors, sensor arrays, and/or other connected peripherals, and are further configured to be mountable and/or attachable to a wide variety of surfaces and objects disposed around a site such as a construction site. The system further comprises a backend, analytic system for making predictions, taking action, and generating reports responsive to the information received from the base units.