Wildfire Academy
The Wildfire Academy explains the science behind the data you see in Wildflyer. Whether you’re learning about fire weather indices for the first time or brushing up on weather variables, you’ll find practical, fire-service-focused explanations here.
Fire Indices
Section titled “Fire Indices”Numerical indices that combine weather data to estimate fire danger.
Fire Weather Index (FWI) The standard European fire danger rating system.
FWI 2025 The 2025 update to the Canadian FWI system.
Hot-Dry-Windy Index (HDWI) Measures the atmosphere's ability to worsen a fire.
Haines Index Atmospheric stability and dryness potential.
Build-Up Index (BUI) Total fuel available for combustion.
Initial Spread Index (ISI) Expected rate of fire spread.
Weather Variables
Section titled “Weather Variables”The individual measurements that drive fire weather forecasting.
Temperature Air temperature and its role in drying fuels.
Relative Humidity How saturated the air is and what it means for fire.
Wind & Gusts The primary driver of fire spread.
VPD The drying power of the atmosphere.
More Topics
Section titled “More Topics” Weather Models The numerical weather prediction models behind our forecasts.
Phases of a Wildfire From ignition to extinguishment.