NOAA's Environmental Real-time Observation Network
The NOAA Environmental Real-time Observation Network (NERON) is a project to establish a nationwide network of high quality near real-time weather monitoring stations across the United States. A 20-mile by 20-mile grid has been established, with the hopes of having one observation system within each grid cell.
Source: Wikipedia — NOAA's Environmental Real-time Observation Network (CC BY-SA 4.0)