The water content of fuel particle expressed as a percent of the oven dried weight of the fuel particle. Fuel moisture observations are generally for the 10-hour time lag fuels (medium-sized roundwood 1/4" to 1" in diameter).
The amount of water in a fuel sample. The proportion of water to dry material. Percent fuel moisture = (Wet weight - Dry weight)/Dry weight * 100. Fire behavior is dependent, to a large extent, on how much water is in the fuel.
Percent water content of vegetation, an important factor in rate of spread, ranging from dead-fuel and fine-fuel moisture (FFM), of 10 percent or less, to live-fuel moisture (LFM), of 60 percent or more. FFM can be estimated by weighing calibrated wood sticks.