Ivory Coast, the world's top cocoa producer, is experiencing its annual dry season, which runs from mid-November to March.
Most of farmers said trees were full of large cocoa pods, ready to be harvested until January.
But in the central regions of Bongouanou, Yamoussoukro and in the centre-western region of Daloa, where rains were well below average, farmers said they no longer expect a good development of enough small and average pods.
"We worry. At this rate there won't be enough cocoa after February," said Antoine Konan, who farms near Daloa.
Data collected by Reuters showed rainfall in Daloa was 1mm last week, 5.1 mm below the five-year average.
In the central region of Bongouanou and Yamoussoukro, farmers reported a mild Harmattan dry wind.
The dusty winds of the Harmattan, which usually sweep down from the Sahara in December-March, were already blowing in the north of the country and moving southward.
When severe, the winds can harm cocoa pods and dry the soil, making beans smaller.
In the eastern region of Abengourou, rains were above average, farmers said, while growing conditions were also good in western region of Soubre. In the southern regions of Divo and Agboville rains were below average.
"All is well on the trees. We're still expecting a good harvest," said Salame Kone, who farms near Soubre, where 12.9 mm fell last week, 2.9 mm below the average.
Last week's average daily temperatures ranged from 26.3 to 28.3 degrees Celsius.
(Reporting by Loucoumane Coulibaly; Editing by Hereward Holland and Barbara Lewis)
By Loucoumane Coulibaly