"The weather has been catastrophic. The summer was very hot and dry, and there wasn't the desired moisture," said Michel Courvoisier of the French truffle growers federation FFT.
"In the autumn we didn't have rain at the right time and the winter was mild," he added.
Southeastern France accounts for nearly three-quarters of national production of the "black diamond", which can fetch some €500 ($550) a
kilo (2.2 pounds).
According to the FFT's estimates, this season's output from the region was around 29 tonnes, compared with last year's 40 tonnes.
Overall production of the delicacy is projected at just 35 tonnes this year, compared with 56 tonnes in 2015.
The finest black truffles have a subtle aroma and an earthy flavour reminiscent of rich chocolate.