About FireWatch

What this is

A wildfire is an unplanned fire burning in vegetation — forest, grassland, shrub or peat. FireWatch tracks them two ways: satellite “hot-spot” detections that flag where something is burning right now, and named incidents with reported size and containment.

Each satellite detection carries a Fire Radiative Power (FRP) value — how much energy the fire is releasing — which FireWatch uses as its intensity scale. More FRP means a more intense burn front, though a single detection is a 375 m–1 km pixel, not a precise fire perimeter.

• 🛰️ How satellites spot firesThermal sensors, the FRP intensity measure, why detections come in batches, and what a hot spot can and cannot tell you.
• 🔥 What makes a fire spreadThe fire triangle, why weather and terrain dominate, and the red-flag conditions that drive explosive growth.
• 📋 Reading incidents and containmentWhat acreage and “percent contained” really mean, and why a fire can be large yet largely controlled — or small yet dangerous.

Wildfire safety

General guidance — always follow local fire authorities and evacuation orders first.

Data sources

• NASA EONET — Curated, continuously updated open wildfire event locations.
• NASA FIRMS — Active-fire detections and FRP from MODIS and VIIRS satellite instruments.
• InciWeb — US interagency incident information — named fires, size and containment.

Frequently asked

Does a hot spot mean there’s definitely a fire?

Usually, but not always. Detections are reliable for real fires yet can be missed under cloud or smoke, and occasionally a very hot industrial source triggers a false flag. Trust clusters of detections and named incidents over a single pixel.

Why do fires appear and disappear between updates?

Satellites only pass over a location a few times a day, so detections come in batches. A fire still burning may show no new hot spots until the next overpass, especially if clouds or smoke block the view.

What does “30% contained” mean?

Crews have secured 30% of the fire’s edge with lines they expect to hold. The other 70% can still be spreading — containment is about the perimeter, not how much fire is left.

Is a bigger fire always more dangerous?

No. Danger depends on what’s nearby and which way the fire is moving. A small fire near homes in steep, windy terrain can be far more threatening than a large fire in remote wilderness.