The U.S. National Lightning Detection Network (NLDN) is a commercial lightning detection network operated by Vaisala. A network of antennae are connected to a central processor that records the time, polarity, signal strength, and number of strokes of each cloud-to-ground lightning flash detected over the United States. Vaisala's U.S. NLDN lightning data detection network consists of more than 100 remote, ground-based lightning sensors. 

The data spatial coverage includes the continental United States and extends 200-300 km off the coastline. The temporal range for millisecond flash data is January 1, 1995, to present; the temporal range for one second flash data is January 3, 1988, to present.

NLDN data are restricted to collaborators that have a working relationship with NASA's Marshall Space Flight Center Lightning Group.