Cooler conditions across Victoria may suggest reduced haystack fire risk, but moist hay continues to heat internally and remains a significant hazard.
Producers are urged to maintain regular monitoring of baled and stacked hay, as no current technology reliably tracks internal hay temperatures.
Dairy Extension Officer, Michele Jolliffe said the real danger in hay is what you can't see, so regular checks remain the strongest protection against fire.
'Simple actions like testing temperatures and watching for warning signs can prevent a heating haystack from becoming a dangerous ignition,' said Ms Jolliffe.
'Warning signs such as steam, roof condensation, mould, acrid smells or humid air near stacks should prompt immediate checks to prevent heat buildup and potential ignition.'
'Most heating occurs within the first fortnight after baling, although hay can still reach ignition point up to eight weeks later especially during fluctuating autumn temperatures.'
'Cooler weather can hide the risk, but moisture in hay can still spark trouble if vigilance drops,' said Ms Jolliffe.
Using a crowbar inserted for two hours remains an effective temperature test, and a bar too hot to hold indicates a dangerous internal temperature above 70°C.
If hay is heating, stacks should be carefully pulled apart to release heat, with water supply and trained personnel on standby to prevent ignition.
Producers should avoid walking on stacks due to potential internal charring, any extra weight on the stack may cause the stack to collapse and cause serious injury.
If there is the slightest risk of a fire starting due to wet hay, never keep machinery in the hayshed and don't allow children to play in or near heating stacks.
