FIELD GUIDE · Satellite & Imagery
How to Track Wildfires and Smoke from Space
How do satellites detect wildfires and track their smoke?
Wildfires move fast and often burn in remote places, which is exactly why satellites have become essential for tracking them. From orbit, two different signals tell the story: the heat of the fire itself, and the smoke it sends downwind.
On the live map, switch on the active fires layer alongside Cloud Imagery to see both at once.
Detecting the fire: heat from infrared
Satellites carry infrared sensors that pick up the intense heat a wildfire radiates. When a sensor detects a hotspot far above normal background temperatures, it logs it as a fire detection point. NASA's FIRMS program publishes these detections freely, typically within a few hours of the satellite pass — which is what powers the fire dots on live maps.
A few things to know:
- Each dot is a heat detection, not the exact fire boundary — clusters of dots trace an active fire front.
- Detections update with satellite passes, so they're near real-time, not continuous.
- Heat sources other than wildfire (industrial flares, agricultural burning) can also register.
Tracing the smoke: true-color satellite
The fire's smoke shows up beautifully on GeoColor satellite imagery, because that imagery is true-color by day — smoke appears as grey-brown plumes streaming downwind. Press play on the loop and you can watch a plume grow and bend with the wind over hours.
This is also where radar falls short: radar can't see smoke at all. For fire, satellite is the tool.
The fusion view
LEV's edge is putting these together: fire hotspots, the satellite smoke plume, and wind — on one map. Switch on the fires and cloud layers over an active fire region and you can see where it's burning and where the smoke is heading at the same time.
Open the live map and explore the fire and satellite layers together.
Frequently asked questions
How do satellites detect wildfires?
Satellites carry infrared sensors that detect the intense heat a fire gives off, even through some haze. Each detected hotspot is plotted as a point on the map. NASA's FIRMS system makes these fire detections freely available, usually within a few hours.
Why can I see smoke but no fire on the map?
Heat detection needs a relatively clear view, so thick cloud or dense smoke can hide the source hotspot, while the smoke plume itself remains visible in true-color satellite imagery. Reading the fire points and the satellite smoke together gives the fullest picture.
SEE IT LIVE
Everything in this guide is on one real-time map.