NASA FIRMS (Fire Information for Resource Management System)

The Fire Information for Resource Management System (FIRMS) is NASA's service for active fire data: points where a satellite has seen a fire or other heat source.¹ It delivers them in near real time to fire managers and the public as maps, email alerts, files and web services.¹ The University of Maryland built it in 2007 with funds from NASA's Applied Sciences Program and the UN Food and Agriculture Organization.² It moved to NASA's near real-time system, LANCE, in 2012 and is run by NASA's Earth Science Data and Information System (ESDIS) project.^1,2 A US/Canada version built with the USDA Forest Service opened in January 2021 and adds context layers from the National Interagency Fire Center, the National Weather Service, the Canadian Interagency Fire Centre and others.²

The core data come from two instruments. MODIS, on NASA's Terra and Aqua satellites, flags pixels of about 1 km; VIIRS, on Suomi NPP, NOAA-20 and NOAA-21, flags pixels of about 375 m and picks up smaller fires and fires at night better.^2,3 Each detection is the centre of a pixel that contains at least one fire, not the fire's own position or size, and several detections in a line usually mark a fire front.³ Every detection carries a confidence value and fire radiative power, the rate of heat given off, which is used as a measure of fire intensity.³ FIRMS also shows a Landsat fire product at 30 m for most of North America, provisional detections from geostationary weather satellites over the Americas, Europe, Africa and Asia, and satellite imagery.³ MODIS records go back to November 2000 and VIIRS to January 2012.³ FIRMS says Suomi NPP deliveries end on 2 November 2026 and users should move to NOAA-20 and NOAA-21.⁵

The satellites generally pass over a place twice a day, more often near the poles.³ Worldwide, detections reach FIRMS within three hours of an overpass; over the United States and Canada a real-time version arrives within 30 minutes and an ultra real-time version within five.³ The fire maps refresh every five minutes, and files for the last 24 hours, 48 hours and 7 days, in shapefile, KML and CSV, every hour.³ Data for the last two months can be downloaded as text, and older data through the archive download tool.³

Access is free. The API returns detections as CSV for a bounding box or the whole world, one to five days at a time, for a chosen satellite source.⁴ It needs a MAP_KEY, sent free to an email address, limited to 5,000 transactions in ten minutes.⁵ Downloading the daily text files needs an Earthdata Login.³ NASA says it promotes full and open sharing of FIRMS data, asks that images be credited "NASA FIRMS", and gives an acknowledgement for scientific papers; the data are provided as is.^2,3

The FAQ sets out what the data cannot do. A fire can be missed if it starts and ends between passes, is hidden by cloud, heavy smoke or tree canopy, or is too small or too cool; fires under a forest canopy are very unlikely to be seen.³ Not every detection is a vegetation fire: volcanoes and gas flares are also flagged, and the near real-time data do not say which.³ The points carry no information on cloud or missing data, so counting them without the other pixel classes can mislead.³ NASA does not recommend estimating burned area from them.³

For a model of a fire-prone county or region, FIRMS is the record of where and when fires have burned since 2000 and a live feed of where they are burning now. The archive can show fire seasons, repeat burns and the places fires start, to set against fuel and land-cover layers such as LANDFIRE; the live feed can drive a situational map or alerts. The pixel-centre points are best read as "fire somewhere in this square", not as perimeters.