Wildfire evidence field guide
CAL FIRE vs InciWeb vs NASA FIRMS: which wildfire source should you use?
They answer different questions. Incident agencies publish operational status and public information; FIRMS provides satellite thermal detections. Good wildfire analysis combines sources without pretending they are interchangeable.
Source roles
No single source contains the whole incident.
Best starting point for California incident summaries, acreage, containment, agency information and California-specific operational layers.
Federal incident public-information pages can include announcements, closures, maps, photos and management-team updates for incidents published there.
Near-real-time satellite active-fire and thermal-anomaly detections from sensors including MODIS and VIIRS.
County sheriffs, emergency managers and transportation agencies can be the authoritative source for local evacuation or road actions.
Use by question
Choose the source based on what you are trying to know.
- Current containment or agency-reported acreage: use the incident-management or jurisdictional source.
- Evacuation order: use the responsible local authority or official incident page linking that authority.
- Satellite heat detected at a time/location: use FIRMS with sensor metadata.
- Mapped fire edge: use a timestamped perimeter dataset, not hotspot points.
- Road closure: confirm with the transportation or law-enforcement authority responsible for the road.
Conflicts
Two official pages can disagree without either being fraudulent.
Publication systems update at different times. One page can show a newer statewide summary while a dedicated incident page still displays an older snapshot. The correct analytical response is to preserve both values with timestamps and provenance until the source systems reconcile.
Examples
Tecnobosque records preserve source evolution.
Primary routes