The overall objective of the handbook is to improve both the reliability and comparability of data collected at fire-weather stations. To accomplish this, the handbook offers uniform standards and procedures designed to avoid, or at least minimize, the major sources of error commonly associated with weather measurement. These sources of error have been identified as: (1) instrumental error; (2) observational error; (3) exposure error; and (4) sampling error (Smith 1970). The standards and procedures provided to deal with the above sources of error are consistent with well-established practices of meteorological organizations and fire control agencies. Publications of the National Weather Service (United States); Meteorological Division, Department of Transport (Canada); World Meteorological Organization (United Nations); USDA Forest Service; and Canada Department of Forestry were major sources for the development of the recommended standards.