Here’s a dramatic example of nighttime fire activity seen in the VIIRS DNB radiance and 3.9 micron bands early in the morning on July 4th. The active fire was the 50,000 acre Papoose fire in southwestern Colorado, one of several large fires in that part of the state, but the only one burning actively enough to have a strong signal at this time. The fire is the bright area surrounded by a large area of dark wilderness in the lower left portion of the picture:
The RGB version of the product reveals some cloud cover in the area, but the light from the fire penetrates as well, appearing similar to some of the large cities in other parts of the state.
The active fire area is also visible in the 3.9 micron imagery:
For comparison, here’s a heat map for the fire from an aircraft overflight at about the same time:
The area of active fire, southeast of the jog in the county line, matches up pretty well. There appears to be more light coming from the area further northwest versus the infrared signal.