Structure of the Canadian forest fire weather index
Document Type: Book
Author(s): C. E. Van Wagner
Publication Year: 1974

Cataloging Information

  • Canada
  • droughts
  • duff
  • energy
  • fine fuels
  • fire danger rating
  • fire intensity
  • fuel management
  • fuel moisture
  • fuel types
  • humidity
  • moisture
  • Ontario
  • pine forests
  • Pinus banksiana
  • Pinus resinosa
  • plantations
  • precipitation
  • rate of spread
  • season of fire
  • temperature
  • weather observations
  • wind
Record Maintained By:
Record Last Modified: July 12, 2018
FRAMES Record Number: 39062
Tall Timbers Record Number: 13689
TTRS Location Status: In-file
TTRS Call Number: Fire File DDW
TTRS Abstract Status: Fair use, Okay, Reproduced by permission

This bibliographic record was either created or modified by the Tall Timbers Research Station and Land Conservancy and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of the Tall Timbers Research Station and Land Conservancy.


The Canadian Forest Fire Weather Index (FWI) was issued in 1970 after several years' work by a number of fire researchers in the Canadian Forestry Service. The best features of the former fire danger index were incorporated in the FWI, and a link was preserved between old and new. The FWI is based on the moisture content of three classes of forest fuel plus the effect of wind on fire behavior. It consists of six components: three primary subindexes representing fuel moisture, two intermediate subindexes reprsenting rate of spread and fuel consumption, and a finl index representing fire intensity as energy output rate per unit length of fire front. The FWI refers primarily to a standard pine fuel but is useful as a general index of forest fire danger in Canada. It is determined every day from noon weather readings only: temperture, relative humidity, wind speed, and rain (if any). This paper describes the developement of the Fire Weather Index, the concepts behind it, and its mathmatical structure

Van Wagner, C. E. 1974. Structure of the Canadian forest fire weather index. Publication No. 1333. Ottawa, Information Canada Department of the Environment, Candian Forest Service.